BY 

.VOQI^HEES 


*H  « 


Ube  IRural  Science  Series 

EDITED  BY  L.  H.  BAILEY 


FERTILIZERS 


Elje  Eural  Science  Serteg 

EDITED  BY  L.  H.  BAILEY 

THE  SOIL.    King. 

THE  SPRAYING  OF  PLANTS.     Lodeman. 

MILK  AND  ITS  PRODUCTS.    Wing.   Enlarged  and  Revised. 

THE  FERTILITY  OF  THE  LAND.     Roberts. 

THE    PRINCIPLES    OF    FRUIT-GROWING.     Bailey.     20ih 

Edition,  Revised. 
BUSH-FRUITS.     Card. 
FERTILIZERS.     Voorhees.     Revised. 
THE  PRINCIPLES  OF  AGRICULTURE.    Bailey.     Revised. 
IRRIGATION  AND  DRAINAGE.     King. 
THE  FARMSTEAD.     Roberts. 
RURAL  WEALTH  AND  WELFARE.     Fairchild. 
THE  PRINCIPLES  OF  VEGETABLE-GARDENING.  Bailey. 
FARM  POULTRY.    Watson.    Enlarged  and  Revised. 
THE  FEEDING  OF  ANIMALS.     Jordan. 
THE  FARMER'S  BUSINESS  HANDBOOK.     Roberts. 
THE  DISEASES  OF  ANIMALS.     Mayo. 
THE  HORSE.     Roberts. 
How  TO  CHOOSE  A  FARM.     Hunt. 
FORAGE  CROPS.     Voorhees. 

BACTERIA  IN  RELATION  TO  COUNTRY  LIFE.     Lipman. 
THE  NURSERY-BOOK.     Bailey. 
PLANT-BREEDING.     Bailey  and  Gilbert.     Revised. 
THE  FORCING-BOOK.     Bailey. 
THE  PRUNING-BOOK.     Bailey. 

FRUIT-GROWING  IN  ARID  REGIONS.  Paddock  and  Whipple. 
RURAL  HYGIENE.     Ogden. 
DRY-FARMING.     Widtsoe. 
LAW  FOR  THE  AMERICAN  FARMER.     Green. 
FARM  BOYS  AND  GIRLS.    McKeever. 
THE  TRAINING  AND  BREAKING  OF  HORSES.    Harper. 
SHEEP-FARMING  IN  NORTH  AMERICA.     Craig. 

CO&PERATION    IN   AGRICULTURE.       Powell. 

THE  FARM  WOODLOT.     Cheyney  and  Wentling. 

HOUSEHOLD  INSECTS.     Herrick. 

CITRUS  FRUITS.     Coit. 

PRINCIPLES  OF  RURAL  CREDITS.     Morman. 

BEEKEEPING.     Phillips. 

SUBTROPICAL  VEGETABLE-GARDENING.     Rolfs. 


FERTILIZERS 


THE    SOURCE,    CHARACTER    AND    COMPOSITION 
OF   NATURAL,  HOME-MADE  AND  MANUFAC- 
TURED FERTILIZERS,  AND  SUGGESTIONS 
AS  TO  THEIR  USE  FOR  DIFFERENT 
CROPS    AND    CONDITIONS 


BY    THE    LATE 

EDWARD  B.  VOORHEES,  A.M.,  D.Sc. 

DIRECTOR   OF   THE    NEW  JERSEY    AGRICULTURAL   EXPERIMENT 

STATIONS,    AND   PROFESSOR   OF   AGRICULTURE 

IN   RUTGERS    COLLEGE 


REVISED    EDITION    BY 

JOHN  H.  VOORHEES,  B.Sc. 

ASSISTANT  AGRONOMIST  NEW  JERSEY  EXPERIMENT  STATION 

INSTRUCTOR   IN   SOIL  FERTILITY,  NEW  JERSEY 

STATE  COLLEGE  OF  AGRICULTURE 


THE   MACMILLAN  COMPANY 
1916 

All  rights  reserved 


COPTBIGHT,  1898 

BY  EDWAED  B.  VOOEHEES 


Set  up  and  electrotypcd.  Published  November,  1898.  Reprinted 
with  corrections  January,  1900;  January  and  February,  1902; 
February,  1903;  August,  1904;  August,  1905;  January,  1907;  March 
and  October,  1908;  February,  April  and  October,  1910;  June,  1911; 
January  and  June,  1912;  August,  1913;  August,  1914. 


EEVISBD  EDITION.     COPYBIGHT,  1916 
BY  JOHN  H.   VOOEHEES 


Set  up  and  electrotyped.    Published  May,  1916. 


:•          .:.  '- 


J.  8.  Cushing  Co.  —  Berwick  &  Smith  Co. 
Norwood,  Mass.,  U.S.A. 


CONTENTS 

CHAPTER  I 

PAGES 

THE  NATURAL  FERTILITY  OP  THE  SOIL  AND  SOURCES  OF 

Loss  OF  THE  ELEMENTS  OF  FERTILITY  .  .  .  1-19 

Soil  Fertility  —  Chemical  elements  needed  in  plant 
growth  —  Fertility  as  influenced  by  water,  climate  and 
season  —  The  influence  of  physical  character  of  soil  — 
Location  of  soil  qualifies  the  term  "fertility" — Prac- 
tical fertility  is  usable  potential  fertility  .  .  .  2-6 

What  Becomes  of  Our  Fertility  ?  7 

Sources  of  Natural  Loss  of  Nitrogen  —  Importance 
of  careful  culture  —  Loss  of  nitrogen  by  drainage  — 
Escape  of  nitrogen  into  the  atmosphere  ....  8-11 

The  Natural  Loss  of  the  Mineral  Elements-^- Losses 
due  to  mechanical  means  .  .  .  .  .  11-12 

Artificial  Losses  of  Fertility  —  A  comparison  of  the 
prices  received  for  the  fertility  elements  in  different 
crops  —  Fertility  content  of  cereals  and  vegetables  — 
Irrational  farm  practice  —  Losses  in  manures  .  .  13-19 

CHAPTER  II 

THE  FUNCTION  OF  MANURES  AND  FERTILIZERS,  AND  THE 

NEED  OF  ARTIFICIAL  FERTILIZERS         ....  20-35 

The  Essential  Elements  of  Fertilizers         ...  20 

Natural  Manures  and  Artificial  Fertilizers         .        .  21 

Direct  and  Indirect  Effect  of  Manures         .        .        .  22-23 

Unavailable  and  Available  Plant-food        .        .        .  23-26 

Danger  of  Loss  from  the  Use  of  Soluble  Plant-food   .  25 
The  Usefulness  of  a  Fertilizer  Constituent  does  not 

Depend  upon  Its  Original  Source 26 

Use  of  Fertilizers 27-28 

v 


3667*., 


vi  Contents 

PAGES 

The  Need  of  Artificial  Fertilizers  —  The  cost  of  pro- 
duction to  a  unit  of  income  is  increased  —  A  greater  de- 
mand for  special  crops  —  Farm  manures  are  inadequate 

—  The  growing  importance  of  fruit-growing  .        .        .        28-33 
Will  it  Pay  to  Use  Fertilizers  f 33-36 

CHAPTER  III 

NITROGENOUS  FERTILIZERS 36-60 

What  is  Meant  by  Form  of  Nitrogen  ?        .        .        .        36-37 

Dried  Blood 37-39 

Dried  Meat  or  Meal,  Azotin,  Ammonite,  or  Animal 

Matter 39 

Dried  and  Ground  Fish,  or  Fish  Guano     .        .        .        39-40 

Tankage 40-41 

Garbage  Tankage 42 

Low-grade    Nitrogenous    Products  —  Horn   meal  or 

ground  horn  —  Leather  meal — Wool  and  hair  waste     .        42-43 
Vegetable  Nitrogenous  Products  —  Cottonseed  meal 

—  Linseed  meal  —  Castor  pomace  —  Vegetable  pomaces        43-44 
Natural  Guanos  —  Mechanical  Condition  should  be 

considered 44-47 

Ammonia  Compounds  —  Sulfate  of  ammonia  — Cal- 
cium cyanamid        ........        47—60 

Nitrate  Nitrogen  —  Nitrate  of  soda  —  Calcium  nitrate 

—  Potassium  nitrate  —  Ammonium  nitrate    .        .        .        60-63 
The  Relative  Availability  of  the  Different  Forms  of 

Nitrogen  —  Comparative  availability  of  different  nitrog- 
enous substances  —  Conditions  which  modify  avail- 
ability    63-60 

CHAPTER  IV 

PHOSPHATES  —  THEIR  SOURCES,   COMPOSITION,   AND  RELA- 
TIVE VALUE    .  61-80 

Phosphate  of  Lime,  or  Bone  Phosphate  —  Animal 
Bone  —  Raw  bone  —  Fine  bone  —  Boiled  and  steamed 
bone  —  Commercial  grades  of  bone  —  Bone  tankage  — 
Other  organic  products  —  Bone-black,  or  animal  char- 
coal—  Bone-ash 62-68 


Contents 


vn 


Mineral  Phosphates  —  South  Carolina  rock  phosphates 

—  Florida  phosphates  —  Canadian  apatite  —  Tennessee 
phosphate  —  Recent  discoveries  in  western  states  —  Basic 
slag  —  Manufactured    phosphates  —  Artificial    basic- 
slag  meal  —  Wiborgh  phosphate  —  Wolter  phosphate  — 
Palmaer  phosphate  —  Phosphatic  guanos        .        .        .        68-76 

Phosphates  as  Sources  of  Phosphoric  Acid  to  Plants 

—  The  influence  of  source  of  phosphate  upon  availability 

—  Influence  of  fineness  of  division — The  character  of 
soil  as  a  factor  influencing  availability  —  Influence  of 

the  kind  of  crop  —  General  considerations      .        .        .        75-80 


CHAPTER  V 


SUPERPHOSPHATES  —  POTASH 81-101 

Insoluble  Phosphoric  Acid 81-82 

Soluble  Phosphoric  Acid 82 

Reverted  Phosphoric  Acid 82-83 

How  Superphosphates  are  Made  —  The  difference  in 
the  superphosphates  made  from  the  different  materials 
—  Soluble  phosphoric  acid  chemically  identical,  from 

whatever  source  derived 83-85 

Phosphates  and  Superphosphates  are  not  Identical     .        85-89 

Double  Superphosphates 89-90 

Chemical  Composition  of  Superphosphates  —  Well- 
made  superphosphates  contain  no  free  acid  —  Phosphoric 
acid  remains  in  the  soil  until  taken  out  by  plants  .  .  90-93 

Potash  Salts  —  The  importance  of  potash  as  a  con- 
stituent of  fertilizers  —  Forms  of  potash  —  Kainit  — 
Hardsalt  —  Carnallit —  Muriate  of  potash  —  High-grade 
sulf  ate  of  potash  —  Double  manure  salt  —  Potash  manure 
salt  —  Double  carbonate  of  potash  and  magnesia  —  Po- 
tassium carbonate  —  Potassium  nitrate  —  Feldspar  and 
other  minerals  as  a  source  of  potash  —  Seaweeds  as  a 
source  of  potash  —  Fixation  of  potash  ....  93-101 


CHAPTER  VI 

MISCELLANEOUS  FERTILIZING  MATERIALS     .... 

Tobacco  Stems  and  Stalks  —  Tobacco  salts  —  Crude 

fish  scrap  —  Wool  and  hair  waste  —  Sewage  —  Muck  and 


102-118 


Vlll 


Contents 


peat  —  King  crab,  mussels  and  lobster  shells  —  Seaweed 
—  Wood-ashes  and  Tanbark-ashes  —  Coal-ashes  —  Cot- 
ton-hull-ashes —  Corn-cob-ashes  —  Cocoa  shells  —  Green 
sand  marl  —  Agricultural  salt  —  Powder  waste  — 
Gas  lime  —  Gypsum  or  calcium  sulfate  —  Phosphorus 
powder  —  Calcium  carbide  waste  —  Oxy-acetylene 
residue  —  Purchase  and  use  of  miscellaneous  materials  . 


118 


CHAPTER  VII 

FARMYARD  AND  GREEN-MANURES 119-134 

Farmyard  Manures  —  Variations  in  manures  —  Ma- 
nure produced  by  different  animals  —  Composition  of 
stable  manure  —  Solid  and  liquid  portions — Sources  of 
loss  in  manures  —  Care  of  manures  —  Manure  preserva- 
tives—  The  improvement  of  manures  —  Application  of 
yard  manure — Poultry  and  pigeon  manure  —  Composts  119-128 

Green-manures  —  "Nitrogen  gatherers"  and  "nitro- 
gen consumers" — The  most  useful  crops  —  Green- 
manure  crops  that  consume  the  nitrogen  in  the  soil  — 
Mixtures  are  advisable  —  Precautions  in  the  use  of 
green-manures  .  . 128-134 


CHAPTER  VIII 

LIMB  AND  CALCIUM  COMPOUNDS  .        .        .        .        .        .     136-152 

Occurrence  of  Lime     .......  136 

Forms  on  the  Market  —  Caustic  lime  —  Ground  lime- 
stone —  Calcium-magnesium  lime  —  Ground  burned 
lime  —  Hydrated  lime  —  Air-slaked  lime  —  Oyster  shell 

lime  — Shell  marl 136-140 

Action  of  Lime  on  Soils  —  Mechanical  effects  of  lime 

—  Chemical  effects  of  lime  —  Lime  supplies  a  necessary 
base  —  Lime  assists  the  decomposition  of  organic  matter 

—  Lime  makes  soil  potash  available  —  Lime  makes  soil 
phosphates  available  —  Less  plant-food  required  —  Inju- 
rious chemical  effects  —  Effects  of  gypsum      .         .        .     140-145 

Biological  Effects  of  Lime  —  Biological  effects  may 
be  harmful  145-146 


Contents 


IX 


The  Use  of  Lime  —  Do  soils  need  lime  ?  —  The  appli- 
cation of  lime  —  When  and  how  to  apply  lime — The 
form  of  lime  to  use  —  Distribution  of  lime  —  Analysis 
and  guarantee 

CHAPTER  IX 


146-152 


PURCHASE  OF  FERTILIZERS 153-174 

Standard  High-grade  Materials 154-156 

Fertilizing  Materials  Variable  in  Composition  .        .     155-156 
High-grade  and  Low-grade  Fertilizers  —  The  "unit" 
basis  of  purchase  —  The  "  ton  "  basis  of  purchase  —  The 
necessity  of  a  guarantee  —  Laws  alone  do  not  fully  pro- 
tect —  Method  of  statement  of  guarantee  sometimes  mis- 
leading —  Discussion  of  guarantees  —  Kaw  materials  — 
Mixed  fertilizers  —  The  advantages  and  disadvantages 
of  purchasing  raw  materials  and  mixed  fertilizers  .        .     166-167 
Home  Mixtures  —  Formulas  —  The  cost  of  handling 

"  make-weight  " 167-173 

General  Advice    .  173-174 


CHAPTER  X 

CHEMICAL  ANALYSES  OP  FERTILIZERS  . 
The  Interpretation  of  an  Analysis 
The  Agricultural  Value  of  a  Fertilizer 
The  Commercial  Value  of  a  Fertilizer 
Calculation  of  Commercial  Values 
The  Uniformity  of  Manufactured  Brands 

CHAPTER  XI 
METHODS  OF  USE  OF  FERTILIZERS 


175-190 
175-178 
178-179 
179-187 
187-188 
188-190 


.     191-211 


Conditions  which  Modify  the  Usefulness  of  Fertilizers 

—  Derivation  of  soil  a  guide  as  to  its  possible  deficiencies 

—  Physical  imperfections  of  sandy  soils  —  Physical  im- 
perfections of  clay  soils  —  The  influence  of  previous 
treatment  and  cropping  —  The  influence  of  character  of 
crop  —  The  kind  of  farming,  whether  "extensive"  or 
"intensive"  . 


191-199 


Contents 


Plants  Vary  in  their  Power  of  Acquiring  Food  — 
Characteristics  of  the  cereal  group  —  Characteristics  of 
grasses  and  clovers  —  Root  crops  —  Market-garden  crops 

—  Fruit  crops 199-204 

Systems  of  Fertilizing  Suggested  —  A  system  based 

upon  the  specific  influence  of  a  single  element  —  A  sys- 
tem based  upon  the  necessity  of  an  abundant  supply  of 
the  minerals  —  A  system  based  on  the  needs  of  the  plants 
for  the  different  elements  as  shown  by  chemical  analysis 

—  A  system  in  which  the  fertilizer  is  applied  to  the 

" money  crop"  in  the  rotation  —  An  irrational  system    204-210 
Summary 210-211 


CHAPTER  XII 
FERTILIZERS  FOR  CEREALS  AND  GRASSES 


212-236 


Experiments  to  Determine  the  Lacking  Element  —  A 
scheme  for  plot  experiments  —  Results  that  may  be  at- 
tained .  .  .  . 214-219 

The  Importance  of  System  in  the  Use  of  Fertilizers  — 
Indian  corn  exhaustive  of  the  fertility  elements — Oats 
—  Barley  —  Wheat  —  Rye  —  Clover  —  Timothy  —  A 
gain  of  fertility  by  the  rotation  system  —  The  necessity 
of  adding  more  plant-food  than  is  required  by  a  definite 
increase  in  crop  —  The  system  should  be  modified  if  no 
farm  manures  are  used   .        .        «  '••  x  .        •        .        .     219-231 
Fertilizers  for  a  Single  Crop  Grown  Continuously    .    231-233 
Fertilizers  for  Meadows      .        .        .        .        .        .    234-235 

Will  this  System  of  Fertilizing  Pay  f.        .        .        .    235-236 


CHAPTER  XHI 
FIELD  TRUCK  CROPS     .        .        ....        .        .    237-259 

Fertilizers  for  Potatoes,  Early  Crop  —  The  time  and 
method  of  application  —  The  amount  to  be  applied  — 

Form  of  the  constituents 238-243 

Late  Potatoes 243-244 

Sweet  Potatoes  —  Fertilizer  constituents  contained  in 
an  average  crop  —  The  application  of  the  fertilizers       .    244-248 


Contents 


xi 


Tomatoes  —  Field  experiments  with  fertilizers  for 
tomatoes  —  Fertilizers  for  the  early  crop  for  different 
conditions  of  soil  —  The  use  of  fertilizers  with  yard  ma- 
nures —  Fertilizers  for  late  tomatoes  ....  248-257 

Peppers  and  Eggplant 267 

Peas  and  Beans 257-258 

Field  Beans 258 

General  Considerations 259 


CHAPTER  XIV 


GREEN  FORAGE  CROPS  . 


260-282 


Cereals  and  Grasses  —  Maize  (corn)  forage  —  Silage 
corn  —  Wheat  and  rye  forage  —  Spring  rye  —  Oats  — 
Oats  and  peas  —  Barley  and  peas  —  Millet  —  Orchard 
grass  —  Italian  rye  grass  —  Bermuda  grass  . 

Clovers  and  Other  Legumes  —  Japan  clover  —  Cow- 
pea  and  soybean  —  Spring  vetch  — Hairy  or  winter 
vetch —  Alfalfa  or  lucerne  —  Sweet  clover  —  Need  of 
lime  for  legumes  —  Fertilization  of  soiling  crops  . 

The  Cabbage  Tribe  —  Rape  —  Cabbage  —  Kohlrabi    . 

Soot  Crops— Fertilizers  for  fodder-beets,  sugar-beets 
and  carrots  —  Turnips  and  swedes  . 

Tuber  Crops 


CHAPTER  XV 


MARKET-GARDEN  CROPS 


The  Yield  and  Quality  Dependent  upon  Continuous 
and  Eapid  Growth — A  basic  fertilizer  for  market-garden 
crops  —  The  different  kinds  of  vegetables 

Boot  Crops  —  Beets  and  turnips  —  Carrots 

Bulb  Crops 

Cole  Crops 

Pot  Herbs 

Salad  Crops  —  Celery  —  Lettuce         .... 

Pulse  Crops         ........ 

Solanaceous  Crops  —  Eggplant  —  Peppers  —  Toma- 
toes   

Vine  Crops 


260-269 


269-277 
277-279 

279-282 


283-307 


283-289 
289-291 
291-293 
293-294 
294-295 
296-296 
296-297 

297-299 
299-300 


Xll 


Contents 


Miscellaneous     Crops  —  Asparagus  —  Rhubarb  — 

Sweet  corn  — Okra 300-306 

Condimental  or  Sweet  Herbs 306-307 

CHAPTER  XVI 

ORCHARD  FRUITS  AND  BERRIES 308-331 

Fruit  Crops  differ  from  General  Farm  Crops     .        .  308-309 
The  Specific  Functions  of  the  Essential  Fertilizing 

Constituents 310 

The  Character  of  Soil  an  Important  Consideration    .  311-312 

The  General  Character  of  the  Fertilizing  .        .        .  312-313 

The  Application  of  Fertilizers  for  Fruits    ...  314 
The  Fertilizing  of  Apples  and  Pears  —  The  amounts 

to  be  applied 314-318 

Peaches  —  The  need  of  fertilizers  —  Methods  of  fer- 
tilizing    . 318-325 

Plums,  Cherries,  and  Apricots   .....  325 

Citrous  Fruits 325-326 

Small    Fruits  —  Strawberries  —  Raspberries    and 

blackberries  —  Currants  and  gooseberries — Cranberries  326-330 

Grapes         , ,  330 


CHAPTER  XVII 
FERTILIZERS  FOR  VARIOUS  SPECIAL  CROPS  . 


332-357 


Cotton  —  Fertilizers  for  cotton  —  Formulas  for  cotton 
fertilizers  — Method  of  application  ....  332-338 

Tobacco  —  The  influence  of  fertilizers  on  the  quality 
of  the  crop  —  The  conclusions  from  Connecticut  experi- 
ments—  Form  of  the  constituents  —  Amounts  to  apply  338-343 

Sugar-beets  —  The  demands  of  the  crop  for  plant-food 

—  The  influence  of  previous  deep  cultivation  of  soil       .     343-346 
Sugar-cane  —  The  needs  of  the  plant  as  indicated  by 

the  Louisiana  experiments  — The  application  of  fertilizers    347-350 

Hops 350-351 

Flax 351 

Miscellaneous  Crops — Sorghum  —  Buckwheat  —  Pea- 
nut —  Roses,  and  other  flowering  plants  —  Lawn  grasses 

—  Forcing  house  crops 351-357 


LIST   OF  ILLUSTRATIONS 


64 
70 


98 


PLATE  I.  Pig.  1.  Coke-oven  Plant,  Gary,  Indiana, 
where  ammonium  sulfate  is  an  important 
by-product opposite  32 

PLATE  II.     Fig.  2.     Cylinder  Experiments  at  the  New 

Jersey  Agricultural  Experiment  Station      .          " 

PLATE  III.     Phosphate  Mining " 

Fig.  3.     Phosphate  Pit,  Dunnellon,  Florida. 
Fig.  4.    Mining  Phosphate  Rock  by  Means  of 
Floating  Dredge. 

PLATE  IV.    Mining  and  Composting  .        .         .        .          " 
Fig.  5.    Mining  Phosphate  Rock  by  Hydraulic 
Pressure. 

FIG.  6.     The  Manure  Spreader  is  a  Labor-saving  Device 

which  secures  an  Even  Distribution  ....    126 

PLATE  IV.     Mining  and  Composting    ....     opposite      98 
Fig.  7.     Unloading  and  Composting  New  York 
Stable  Manure  in  South  Jersey. 

PLATE  V.    Fertilizers  and  Wheat        ....          "          120 
Figs.  8  and  9.  Continuous  Wheat  Cropping  with 
and  without  Green-manures,  New  Jersey 
Experiment  Station. 

PLATE  VI.     Wheat  and  Potatoes         ....          "          140 
Fig.  10.    Wheat   Grown   as   a   Winter   Cover- 
crop   Preceding    Potatoes,  Freehold,   New 
Jersey. 

PLATE  VII.    Fertilizers  and  Rye         ....          "          168 
Figs.  11  and  12.      Rye  with  One-half  Ton  of 
Lime  and  without  Lime, 
xiii 


XIV 


List  of  Illustrations 


PLATE  VI.     Wheat  and  Potatoes         .... 
Fig.  13.     Making  an  Application  of  One  and 
One-half  Tons  of  Quicklime  to  the  Acre  for 
Alfalfa  after  Potatoes. 

FIG.  14.    Grain  Drill  with  Fertilizer  Sower 

PLATE  VIII.     Wheat  and  Timothy      .... 

Fig.  15.  Thirty-five  Bushels  of  Wheat  to  the 
Acre,  Mechanicsburg,  Pennsylvania. 

Fig.  16.  Early  Spring  Top-Dressing  with  Com- 
mercial Fertilizer  High  in  Available  Nitrogen 
Greatly  Increases  the  Yield  of  Timothy. 

PLATE  IX.     Lima  Beans  and. Potatoes 

Fig.  17.  Ninety-acre  Field  of  Lima  Beans  for 
Canning,  Freehold,  New  Jersey. 

FIG.  18.  The  Potato-planter  with  Fertilizer  Attach- 
ment, which  distributes  Fertilizer  evenly  in 
the  Kow  •  «  . 

PLATE  IX.     Lima  Beans  and  Potatoes 

Fig.  19.  One  Ton  of  High-grade  Fertilizer  Used 
upon  Early  Potatoes  is  the  Common  Practice 
among  Growers  in  New  Jersey. 

PLATE  X.     Fertilizers  and  Tomatoes  .        .        .        * 
Fig.  20.     Early    Tomatoes    Grown    in    Light, 

Sandy  Soil,  Thorofare,  New  Jersey. 
Fig.  21.     Growth  of  Clover  along  Tomato  Rows 

Heavily    Fertilized    the    Preceding    Year, 

Moorestown,  New  Jersey. 

PLATE  XI.     Peppers  and  Red  Clover  .        .      .  .  '      ... 
Fig.  22.  Peppers  Grown  under  Field  Conditions, 
Thorofare,  New  Jersey. 

PLATE  XII.  Fig.  23.  Oats  and  Canada  Field  Peas 
respond  to  Good  Fertilization 

PLATE  XI.    Peppers  and  Red  Clover  .        . 

Fig.  24.  Excellent  Second  Growth  of  Red 
Clover  on  Heavily  Fertilized  Potato  Land, 
Freehold,  New  Jersey. 


opposite 


PAGE 

140 


.     213 
opposite    178 


202 


240 


opposite  202 


220 


234 


260 
234 


List  of  Illustrations 


XV 


PLATE  XIII.  Fig.  25.  Dwarf  Essex  Kape  mixed  with 
Soybeans  and  Sweet  Clover,  and  Heavily 
Fertilized,  makes  a  Luxuriant  Forage 

FIG.  26.     Garden  Fertilizer  Sower 


FIG.  27. 


Garden  Fertilizer  Sower  with  Hoe  to  work 
Fertilizer  into  Surface  Soil  . 


PLATE  XIV.     Cabbage  and  Watermelons    . 

Fig.  28.    Cabbage  Heavily  Fertilized,  Freehold, 

New  Jersey. 
Fig.   29.      Watermelons,    Peppers,    and    Corn 

Fertilized  with  Basic  Fertilizer,  Clarksboro, 

New  Jersey. 

PLATE  XV.  Fertilizers  for  Peaches  .... 
Figs.  30  and  31.  Views  of  the  Vineland  Experi- 
mental Peach  Orchard,  New  Jersey  Experi- 
ment Station,  showing  (Fig.  30)  Effect  of 
Nitrogen  in  Addition  to  Minerals  ;  Fig.  31, 
below,  Minerals  Only,  No  Nitrogen. 

PLATE  XVI.      Fig.   32.      Tobacco,    Lancaster    area, 
Pennsylvania 


opposite    278 
.     284 


.     288 
opposite    294 


318 


FERTILIZERS 


CHAPTER  I 

NATURAL  FERTILITY  OF  THE  SOIL,  AND 
SOURCES  OF  LOSS  OF  THE  ELEMENTS  OF 
FERTILITY 

THERE  is  no  one  question  of  greater  importance  to 
the  farming  industry  than  that  of  soil  fertility.  In 
order  that  the  industry  may  be  successful,  it  is  not  enough 
to  produce  crops;  it  is  necessary  that  their  production 
shall  result  in  a  genuine  profit.  That  is,  it  is  not  enough 
to  produce  crops  which  bring  more  than  they  cost  in  the 
way  of  labor  and  manures,  without  taking  into  consid- 
eration the  effect  of  their  growth  upon  the  future  pro- 
ductive capacity  of  the  soil.  The  relation  of  the  outgo 
and  income  of  the  fertility  elements  is  an  important 
factor  in  determining  profits,  and  must  be  considered. 
The  farmer  who  secures  crops  that  bring  more  than  they 
cost,  and  who,  at  the  same  time,  maintains  or  even 
increases  the  productive  capacity  of  his  soil,  is,  other 
things  being  equal,  the  broadly  successful  farmer.  Many 
farmers  are  able  to  accomplish  this  object  because  of  the 
knowledge  they  have  acquired  through  long  years  of 
experience,  rather  than  because  they  possessed  in  the 
beginning  of  their  work  a  definite  knowledge  of  the  fun- 
damental principles  involved  in  crop  production,  and 


2  Fertilizers 

upon  the  observance  of  which  their  success  depended. 
One  of  the  first  needs,  therefore,  in  the  use  of  commercial 
fertilizers  is  a  more  or  less  definite  knowledge  of  what 
constitutes  fertility,  and  of  the  principles  which  under- 
lie crop  production. 

SOIL  FERTILITY 

The  full  meaning  of  the  term  "soil  fertility"  is  not 
easily  expressed,  since  many  conditions  are  involved, 
all  of  which  exert  more  or  less  influence.  The  po- 
tential fertility,  which  is  measured  by  the  total  content 
of  the  food  elements  contained  in  a  soil,  is  made  prac- 
ticable, or  usable,  in  proportion  as  the  conditions  are 
favorable.  The  more  important  of  these  influencing 
conditions  are  here  briefly  discussed.  In  the  first  place, 
it  is  of  the  utmost  importance  that  a  soil  should  contain 
those  elements  found  in  the  plant;  hence,  it  is  almost 
self-evident  that  a  fertile  soil  must  contain  a  maximum 
quantity  of  those  particular  elements  or  constituents 
which  are  removed  from  the  land  in  maximum  amounts 
by  the  crops  grown.  The  removal  of  crops  rapidly  ex- 
hausts the  soil  of  these  elements,  and  finally  reduces  the 
quantity  contained  in  the  soil  to  so  low  a  point  as  to  make 
profitable  cropping  impossible. 

Chemical  elements  needed  in  plant  growth. 

Careful  studies  and  experiments  have  shown  that 
plants  actually  take  from  the  soil  at  least  ten  chemical 
elements  which  are  required  for  their  normal  growth  and 
development:  viz.,  nitrogen,  potassium,  phosphorus, 
magnesium,  sulfur,  sodium,  iron,  chlorin,  silicon  and 
calcium.  Besides  these  elements,  others  are  often  found, 
including  manganese.  It  is  not  to  be  inferred  that  all 


Natural  Fertility  of  the  Soil  3 

of  these  elements  are  required  by  all  plants.  There 
are  many  plants  which  grow  to  maturity  without 
sodium,  silicon  and  chlorin,  but  all  of  the  others  must 
be  present  for  normal  growth.  Carbon,  hydrogen  and 
oxygen  are  also  found  in  plants,  but  these  elements  are 
secured  from  air  and  moisture. 

The  number  of  soil  constituents  liable  to  rapid  exhaus- 
tion is  limited  in  many  cases  to  three,  and  at  most  to  four, 
which  are  nitrogen,  phosphoric  acid  (phosphorus), 
potash  (potassium),  and  lime  (calcium),  the  latter  only 
in  exceptional  cases.  These  are  liable  to  be  exhausted 
because  they  exist  in  larger  amounts  than  the  others  in 
the  plants  that  are  grown,  and  in  smaller  amounts  than 
the  others  in  even  the  most  fertile  soils.  It  has  also  been 
proved  that  it  is  the  one  element  of  these  which  exists  in 
the  smallest  amount  which  measures  the  crop-producing 
power,  or  fertility,  in  this  respect,  as  one  element  cannot 
substitute  or  exert  the  full  functions  of  another.  That  is, 
there  may  be  a  relative  abundance  in  the  soil  of  potash 
and  of  phosphoric  acid,  but  practically  no  nitrogen,  in 
which  case  good  crops  of  cereals,  for  instance,  could  not 
be  grown,  because  no  other  element  can  substitute  the 
nitrogen  required  by  the  plant,  and  it  can  be  obtained  by 
it  from  no  other  source  than  the  soil ;  and  the  soil,  for  all 
practical  purposes,  is  quite  as  unproductive,  lacking  in 
productive  fertility,  as  it  would  be  if  it  contained  much 
smaller  amounts  of  the  mineral  elements  mentioned,  and 
thus  be  poorer  in  potential  fertility. 

Fertility  as  influenced  by  water,  climate  and  season. 

In  the  second  place,  there  are  soils  that  are  so  rich 
in  all  of  these  elements  that  if  productiveness  depended 
upon  them  alone,  maximum  crops  might  be  grown  for 


4  Fertilizers 

centuries  without  exhausting  them,  while  actually  they 
are  now  incapable  of  producing  a  single  profitable  crop 
of  cereals,  grasses,  fruits  or  other  products  of  the  farm, 
because  certain  other  conditions  which  are  essential,  in 
order  to  bring  them  into  activity,  are  absent.  For  ex- 
ample, it  may  be  that  water,  which  is  absolutely  essen- 
tial both  for  the  solution  of  these  food  elements  in  the 
soil,  as  well  as  for  their  distribution  in  the  plant  after  they 
have  been  acquired,  cannot  be  obtained,  or  that  the  tem- 
perature of  the  soil  and  of  the  surrounding  air  is  either 
too  low  or  too  high,  thus  preventing  or  interrupting  the 
progress  of  those  changes  which  must  go  on,  both  in  the 
soil  and  in  the  plant,  in  order  that  normal  growth  and 
development  may  be  accomplished.  With  a  full  supply  of 
the  fertility  elements  in  the  soil,  the  climatic  and  seasonal 
conditions  exert  an  important  influence  upon  its  produc- 
tive power. 

It  is  evident,  therefore,  that  the  chemical  elements  of 
fertility  in  themselves  are  not  sufficient  to  constitute  what 
we  understand  by  the  term.  Fertility  is  not  measured 
by  them  alone ;  associated  with  them  there  must  be  other 
conditions.  That  is,  while  crops  cannot  be  grown  with- 
out these  elements,  it  is  the  conditions  which  surround 
them  that,  in  a  large  degree,  determine  the  power  of  the 
crop  to  secure  them. 

The  influence  of  physical  character  of  soil. 

In  the  third  place,  the  physical  character  of  a  soil  is 
also  a  factor  in  determining  actual  fertility.  This  has 
reference,  first,  to  the  original  character  of  the  rocks  from 
which  the  soil  particles  were  derived,  whether  hard  and 
dense  in  their  mineral  character,  thus  resisting  the  pene- 
tration and  the  solvent  effect  of  air  and  water  and  other 


Natural  Fertility  of  the  Sail  5 

agencies,  or  whether  soft  and  friable,  and  freely  permit- 
ting their  entrance  and  action;  and  secondly,  whether, 
in  the  formation  of  the  soil,  the  particles  were  so  fine 
and  so  free  from  vegetable  matter  as  to  settle  in  hard 
and  compact  masses,  impervious  to  water,  air  and 
warmth;  or  whether  they  were  coarse,  and  not  ca- 
pable of  close  compaction,  thus  giving  rise  to  an  open 
and  friable  soil,  freely  admitting  the  active  natural 
agencies,  such  as  we  find  to  be  the  case  in  sandy  soils. 
In  addition  to  these  properties  of  soils,  which  have  a 
distinct  place  in  determining  fertility,  there  are  many 
other  minor  ones  which  together  constitute  what  is 
understood  as  "condition." 

Location  of  soil  qualifies  the  term  "fertility." 

Furthermore,  fertility,  even  in  this  true  sense,  may 
be  useless  because  of  the  location  of  the  soil  which 
possesses  it.  For  example,  there  are  many  places  on 
this  continent  where  sugar-producing  plants  will  grow 
and  develop  perfectly,  since  the  soils  are  very  rich  in 
the  fertility  elements,  and  since  the  surrounding  con- 
ditions are  most  favorable  for  their  culture,  yet,  be- 
cause of  their  location,  it  is  unprofitable  to  grow  them 
for  the  manufacture  of  sugar.  In  the  first  place,  the 
soils  are  so  situated  as  to  make  it  impossible,  or  at 
least  impracticable,  to  provide  the  means  necessary  for 
converting  the  sugar-producing  crop  into  actual  sugar, 
and,  in  the  second  place,  even  if  it  were  possible  to 
do  so,  the  great  distance  from  shipping  stations  to 
markets  so  increases  the  cost  of  transportation  as  to 
make  it  unprofitable  to  compete  in  the  market  with  the 
crops  grown  upon  lands  possessing  true  fertility  in  a  lower 
degree. 


6  Fertilizers 

Practical  fertility  is  usable  potential  fertility. 

Practical  fertility,  therefore,  is  dependent  upon  many 
conditions,  and  fortunately  our  own  country  possesses  it 
in  a  marked  degree ;  that  is,  the  utility  of  the  potential 
fertility,  as  represented  by  the  total  mineral  content  of 
our  soil,  is  such  as  to  make  us  one  of  the  greatest  agricul- 
tural nations  in  the  world,  both  in  the  quantity  and  variety 
of  products  grown.  Our  soils  possess  the  essential  ele- 
ments in  lavish  amounts,  and  our  climatic  and  seasonal 
conditions  are  such  as  to  permit  of  their  ready  conversion 
into  a  wide  series  of  valuable  products,  and  our  location 
and  facilities  for  handling  and  distributing  our  staple 
crops  are  such  as  to  enable  us  to  compete  in  any  market 
of  similar  commodities. 

Notwithstanding  the  truth  of  this  general  statement, 
it  is  also  true  that  in  certain  sections  of  our  country 
profitable  crops  cannot  be  grown  without  the  addi- 
tion of  commercial  fertilizers,  because  the  soils  are 
either  naturally  poor,  or  they  have  become  partially 
exhausted  of  their  plant-food  elements.  That  is,  the 
amounts  that  become  available  to  the  plant  through 
the  growing  season  are  not  sufficient  to  enable  the  plant 
to  reach  a  maximum  development,  though  other  condi- 
tions are  perfect. 

Our  future  progress  depends,  therefore,  upon  how  well 
we  understand  and  apply  the  principles  which  are  in- 
volved, both  in  the  conservation  and  use  of  the  fertility 
stored  up  in  our  soils,  and  in  the  use  of  purchased  fertility ; 
and  in  this  connection  it  is  important  to  consider  the 
sources  of  loss  of  the  essential  fertility  elements,  or  those 
which  in  the  beginning  measured  our  capabilities  in  crop 
production. 


Natural  Fertility  of  the  Soil  7 

WHAT   BECOMES   OF   OUR   FERTILITY? 

Since  fertility  is  dependent  upon  so  many  conditions, 
or,  in  other  words,  since  the  essential  elements  of  fertility 
are  dependent  upon  their  utility,  and  since,  in  this  sense, 
fertility  is  largely  determined  by  natural  conditions,  it  is 
pertinent  to  inquire,  first,  whether  under  our  present 
systems  of  management,  or  mismanagement,  of  the  land, 
it  is  suffering  any  natural  loss  of  fertility.  As  already 
pointed  out,  the  most  important  function  of  fertility  is 
to  furnish  nitrogen,  phosphoric  acid  and  potash,  and 
since  the  content  of  these  in  our  soil,  together  with  the 
knowledge  we  have  as  to  their  use,  measures,  in  a  sense, 
our  prosperity  as  an  agricultural  people,  the  possibilities 
of  losing  them  from  the  soil  is  a  matter  of  national  con- 
cern, and  is  of  vital  interest  to  individual  farmers,  who, 
in  the  aggregate,  make  up  that  part  of  the  nation  directly 
affected  by  the  results  of  such  loss. 

It  would,  perhaps,  be  possible,  by  a  careful  chemical 
survey  of  our  soils,  to  determine  both  the  actual  and 
potential  fertility  of  our  entire  country,  and  this  knowl- 
edge, together  with  an  accurate  measure  of  the  intelli- 
gence exercised  in  its  use,  would  enable  a  prediction  as 
to  our  future  development,  if  present  methods  were  con- 
tinued. That  is,  whether  our  land  would  become  barren 
and  worthless,  as  has  been  the  case  in  many  older  coun- 
tries which  at  one  time  were  quite  as  productive,  or 
whether  it  would  constantly  increase  in  productiveness, 
even  with  continuous  and  profitable  cropping, — although, 
as  already  pointed  out,  the  present  barrenness  or  sterility 
of  a  country  formerly  fertile  may  not  be  due  entirely 
either  to  the  natural  or  to  the  artificial  loss  of  these 
constituents. 


8  Fertilizers 


SOUKCES  OF  NATURAL  LOSS  OF  NITROGEN 

Of  the  essential  constituent  elements,  nitrogen  is,  in 
one  sense,  of  the  greatest  importance ;  first,  because  it  is 
the  one  that  is  more  liable  to  escape  than  the  others,  and 
secondly,  because  it  is  more  expensive  to  supply  arti- 
ficially than  are  the  minerals.  It  is  the  most  elusive  of 
all  the  elements:  to-day  it  may  be  applied  to  the  soil, 
to-morrow  it  may  be  carried  in  streams  to  the  ocean. 
It  is  also  unstable  —  which  is  not  the  least  valuable  of 
its  characteristics  if  properly  understood:  to-day  it  is 
an  element  of  the  atmosphere,  to-morrow  it  is  a  con- 
stituent part  of  a  growing  plant,  the  next  day  the  same 
element  may  exist  as  an  animal  product,  and  the  day 
following  it  may  be  returned  to  the  soil  to  feed  the  plant. 
It  is  more  liable  to  escape  than  any  of  the  others,  because 
it  is  available  as  plant-food  largely  in  proportion  as  it 
changes  to  a  nitrate,  and  after  it  assumes  that  form  it  is 
seldom  absorbed  or  fixed  in  the  soil.  Nitrogen  in  this 
form  remains  freely  movable,  and  the  probability  of  loss 
by  leaching  is  increased  in  direct  proportion  to  the  lack 
of  preventive  measures  used,  or  the  presence  of  those 
conditions  which  favor  leaching.  The  latter  may  be 
classified  as  follows :  First,  the  amount  and  time  of  the 
rainfall ;  secondly,  the  absorptive  and  retentive  power  of 
the  soil  and  subsoil,  due  to  their  mineral  and  physical 
character;  and  thirdly,  the  amount  of  vegetable  matter 
(humus)  acquired  by  the  soil,  which  retards  the  passage 
of  water.  While  the  amount  and  tune  of  rainfall  can- 
not be  controlled,  its  effect  upon  our  soils  in  this  direction 
can  be  largely  governed  if  proper  attention  is  given  to 
correcting  the  other  conditions,  and  these  may  be  largely 
modified,  if  not  entirely  controlled.  In  the  matter  of  the 


Natural  Fertility  of  the  Soil  9 

absorptive  and  retentive  power  of  soils,  it  has  been  shown 
that  if  they  are  well  supplied  with  vegetable  matter  and 
carefully  cultivated,  they  retain  and  hold  the  plant-food 
constituents  in  a  much  greater  degree  than  if  devoid  of 
humus  and  improperly  managed,  and  also  that  the  drain- 
age water  from  soils  upon  which  crops  are  growing  sel- 
dom contains  more  than  the  merest  trace  of  nitrates. 
The  loss  of  nitrogen  through  the  operation  of  the  forces 
of  nature  may,  therefore,  be  reduced  by  the  careful 
management  of  the  soil. 

Importance  of  careful  culture. 

The  presence  of  suitable  amounts  of  vegetable  matter, 
and  good  cultivation,  are  conditions  that  are  within  the 
power  of  all  farmers  to  provide,  though  it  is  sometimes 
impracticable  to  keep  the  land  continuously  covered  with 
a  crop ;  and  sometimes  it  is  thought  that  the  loss  incurred 
through  leaching  because  of  the  absence  of  a  growing  crop 
is  more  than  balanced  by  the  gain  in  other  directions. 
For  example,  though  losses  of  nitrates  may  occur,  the  gain 
in  availability  of  the  mineral  constituents,  phosphoric 
acid  and  potash,  with  the  accompanying  improvement 
in  texture,  due  to  the  exposure  of  the  soil  to  atmospheric 
influence,  more  than  balances  these  losses,  particularly 
during  the  winter,  with  its  wide  changes  of  temperature. 

Loss  of  nitrogen  by  drainage. 

It  has  been  shown  by  carefully  conducted  experiments, 
both  in  this  and  other  countries,  that  in  a  season  of  aver- 
age rainfall  the  drainage  waters  carry  away  from  one 
acre,  from  uncropped  soils  only  fairly  rich  in  plant- 
food,  as  much  as  37  pounds  of  nitrogen  a  year,  while 
when  continually  cropped  the  drainage  waters  from  the 


10  Fertilizers 

same  soils  contain  practically  no  nitrogen.  This  differ- 
ence in  the  loss  of  nitrogen  under  the  two  conditions  may 
not  seem  a  great  matter  at  the  first  glance,  but  a  careful 
study  of  the  bearing  of  this  loss  in  its  relation  to  crop 
production  shows  that  it  is  really  a  serious  matter.  In 
the  first  place,  the  amount  of  possible  loss  annually  is 
practically  equivalent  in  nitrogen  to  the  amount  con- 
tained in  two  tons  of  timothy  hay,  or  in  one  ton  of  either 
wheat,  rye,  oats,  corn  or  buckwheat,  quantities  nearly 
double  the  average  yield  to  an  acre  of  these  crops  through- 
out our  whole  country ;  and  in  the  second  place,  that  the 
nitrogen  which  is  carried  away  by  the  drainage  water  is 
in  the  very  best  form  for  feeding  the  plant,  or  it  would 
not  have  been  lost,  and  thus  its  loss  leaves  the  soil  not 
only  poorer  in  this  constituent  element,  but  poorer  in 
the  sense  that  the  remainder  of  it  in  the  soil  is  in  a  less 
useful  form.  Furthermore,  if  this  nitrogen  is  to  be  re- 
turned to  the  soil  in  the  same  form,  which  is  the  cheapest, 
it  would  cost  at  present  prices  $6.85. 

Escape  of  nitrogen  into  the  atmosphere. 

Another  source  of  natural  loss  of  nitrogen  is  its  escape 
from  the  soil  as  gas  into  the  atmosphere.  This  is  due  to 
the  oxidation  of  the  vegetable  matter,  or  to  "denitrifica- 
tion,"  which  takes  place  very  rapidly  when  soils  rich  in 
vegetable  matter  are  improperly  managed.  The  possi- 
bilities of  loss  in  this  direction  are  strongly  shown  by  in- 
vestigations carried  out  at  the  Minnesota  Experiment 
Station  on  "the  loss  of  nitrogen  by  continuous  wheat 
raising."  The  results  of  these  studies  show  that  the  total 
natural  loss  of  nitrogen  annually  was  far  greater  than  the 
loss  due  to  the  cropping.  In  other  words,  by  the  system 
of  continuous  cropping,  which  is  universally  observed  in 


Natural  Fertility  of  the  Soil  11 

the  great  wheat  fields  in  the  Northwest,  there  were  but 
24.5  pounds  of  nitrogen  removed  in  the  crop  harvested, 
while  the  total  loss  to  the  acre  was  171  pounds,  or  an 
excess  of  146  pounds,  a  large  part  of  which  loss  was  cer- 
tainly due  to  the  rapid  using  up  of  the  vegetable  matter 
by  this  improvident  method  of  practice.  Whereas,  on 
the  other  hand,  when  wheat  was  grown  in  a  rotation  with 
clover,  the  gain  in  soil  nitrogen  far  exceeded  that  lost  or 
carried  away  by  the  crop.  The  continuous  wheat-  and 
corn-growing  in  the  West,  and  of  cotton  and  tobacco 
in  the  southern  states,  are  responsible  for  untold  losses 
in  this  expensive  element  of  fertility,  while  in  nearly 
every  state  of  the  Union,  soils  both  rich  and  poor  are 
suffering  more  or  less  from  the  effect  of  natural  losses  in 
this  direction. 

THE  NATURAL  LOSS  OF  THE  MINERAL  ELEMENTS 

In  the  case  of  the  minerals,  phosphoric  acid  and  potash, 
which  exist  in  fixed  compounds  in  the  soil,  the  actual 
losses  are  undoubtedly  very  much  less  than  is  the  case 
with  nitrogen,  since  only  traces  of  these  constituents 
are  ever  found  in  solution  in  the  drainage  waters  under 
ordinary  circumstances;  yet,  because  of  the  large  quan- 
tity of  water  that  passes  through  many  of  our  soils,  the 
total  amount  of  these  rendered  soluble  and  carried  away 
by  this  means  is  very  great.  Our  great  rivers  carry  in 
solution  into  the  ocean  tons  upon  tons  annually  of  these 
elements  of  fertility,  and  it  is  an  absolute  loss,  as  there  is 
no  natural  means  by  which  these  may  be  returned  to  the 
soil,  as  is  the  case  with  nitrogen ;  and  it  is  true,  as  in  the 
case  of  the  former,  that  the  soil  is  not  only  absolutely 
poorer  by  virtue  of  the  loss  of  its  elements  of  fertility, 


12  Fertilizers 

but  poorer  in  the  sense  that  the  immediate  utility  of  those 
remaining  is  reduced.  These  silent  and  unseen  forces 
constantly  at  work  are  reducing  the  content  of  these  con- 
stituents in  our  soils  to  an  alarming  degree,  and  it  is 
because  they  are  unrecognized  forces  that  the  disastrous 
results  of  their  activity  are  not  fully  appreciated,  and, 
consequently,  the  best  means  for  restoring  them  are  not 
used. 

Losses  due  to  mechanical  means. 

A  serious  loss  of  all  the  fertility  elements  is  also  due 
to  mechanical  means.  Aside  from  the  amounts  that  the 
rivers  of  water  are  carrying  in  solution  into  the  seas,  im- 
mense amounts  are  carried  in  them  in  suspension.  The 
results  of  this  kind  of  loss  are  painfully  evident ;  in  many 
of  the  southern  states,  and  in  sections  where  the  forests 
have  been  removed  and  the  land  abandoned,  the  soils 
have  been  washed  and  gullied  until  not  only  the  very 
best  portions,  but  in  some  cases  the  largest  portions,  have 
been  carried  away. 

It  is  not,  however,  in  the  abandoned  parts  of  the  coun- 
try alone  that  these  mechanical  losses  of  constituents  are 
of  importance  —  they  are  more  or  less  apparent  on  every 
farm,  and  are  measured  by  the  methods  of  management. 
Soils  that  are  allowed  to  lie  bare  and  fully  exposed  to  the 
storms  of  wind  and  rain  throughout  the  larger  part  of  the 
year  suffer  the  greatest  loss,  while  from  those  which,  on 
the  other  hand,  have  crops  growing  during  a  large  part 
of  the  year,  and  which  hold  the  soil  particles  together  and 
prevent  their  easy  movement,  the  losses  are  reduced  in 
both  the  directions  mentioned.  The  beneficial  results  de- 
rived from  the  use  of  good  methods  are  cumulative ;  the 
benefit  is  not  only  immediate,  but  continuous. 


Natural  Fertility  of  the  Soil  13 


ARTIFICIAL  LOSSES  OF  FERTILITY 

In  addition  to  these  natural  losses  of  fertility,  there  are 
the  artificial  losses  of  the  constituents,  or  those  due  to 
the  removal  of  crops.  These,  of  course,  necessarily  ac- 
company all  farming  operations,  and,  provided  that  in 
the  removal  and  sale  of  the  constituents  in  the  form  of 
crops,  the  farmer  has  received  a  fair  price  for  them,  they 
are  entirely  legitimate. 

The  sale  of  farm  products  is  really  in  the  last  analysis 
a  sale  of  actual  constituents,  together  with  a  certain  por- 
tion of  the  "condition"  of  the  land,  which  is  not  readily 
measurable.  That  is,  it  is  the  constituents  in  the  soil, 
together  with  the  conditions  surrounding  it,  that  the 
farmer  buys  when  he  buys  land.  If  an  acre  of  land,  con- 
taining within  the  reach  of  the  roots  of  the  plant,  say, 
3000  pounds  of  nitrogen,  5000  pounds  of  phosphoric 
acid  and  6000  pounds  of  potash,  sells  for  $100,  the  seller 
receives  the  $100,  not  for  so  much  dirt,  but  really  for  the 
constituents  contained  in  it.  The  purchaser  believes 
that,  with  the  conditions  surrounding  them,  he  can  con- 
vert them  into  products  which  he  can  sell  and  from  which 
realize  a  profit.  If  in  selling  these  amounts  of  the  con- 
stituents in  the  form  of  land,  a  lower  price  to  the  acre  is 
received,  it  is  because  the  natural  conditions  which  sur- 
round them,  and  which  influence  their  utility,  are  less 
favorable,  and  a  greater  proportionate  effort  and  expense 
are  necessary  to  secure  them  in  the  form  of  salable  prod- 
ucts. The  difference  in  the  price  of  land  is  not  always 
due  to  the  content  of  the  constituents,  but  often  to  the 
conditions  surrounding  them.  In  many  cases,  the  soil 
may  serve  simply  as  a  medium  in  which  plants  can  grow, 
and  the  content  of  the  fertility  elements  is  of  minor  im- 


14  Fertilizers 

portance.  Such  would  be  the  case  in  the  growing  of 
market-garden  crops  near  large  cities,  the  location  near 
the  consumer  being  of  greater  importance,  in  the  case  of 
perishable  crops  of  this  sort,  than  the  chemical  character 
of  the  soil.  In  the  larger  number  of  cases,  however,  the 
natural  fertility  fairly  measures  the  market  price.  At  the 
price  to  the  acre,  and  for  the  quantity  of  constituents  here 
assumed,  the  buyer  would  pay  at  the  rate  of  ij  cents  a 
pound  for  the  nitrogen,  and  J  cent  a  pound  each  for  the 
phosphoric  acid  and  potash,  and  it  now  constitutes  his 
capital  stock. 

A  comparison  of  the  prices  received  for  the  fertility  elements 
in  different  crops. 

A  comparison  of  the  prices  paid  for  the  constituents 
in  land,  with  the  prices  received  for  the  same  constituents 
when  contained  in  the  different  crops  (disregarding  for 
the  moment  the  value  of  the  "condition"  of  soil),  will 
make  clearer  this  matter  of  rational  sale  of  constituents, 
which  represents  a  reduction  of  our  capital  stock  of  fer- 
tility. For  example,  if  wheat  is  raised  which  contains 
1.89  per  cent  of  nitrogen,  .93  per  cent  of  phosphoric  acid 
and  .64  per  cent  of  potash  —  or  in  round  numbers,  38 
pounds  of  nitrogen,  19  of  phosphoric  acid  and  13  of  potash 
to  a  ton  —  and  is  sold  for  80  cents  a  bushel,  or  $26.65 
a  ton,  the  nitrogen  sells  in  this  form  for  55  cents  a  pound, 
and  the  phosphoric  acid  and  potash  for  18  cents  each  a 
pound.  That  is,  the  80  cents  a  bushel,  or  the  55  cents  a 
pound,  received  for  the  nitrogen,  and  18  cents  for  the 
potash  and  phosphoric  acid,  represent  what  has  been 
received  for  a  pound  for  the  capital  stock  of  these  ele- 
ments, which  at  $100  an  acre  were  purchased  at  the  prices 
previously  mentioned ;  1 J  cents  a  pound  for  the  nitrogen 


Natural  Fertility  of  the  Soil  15 

and  J  cent  a  pound  for  the  phosphoric  acid  and  potash. 
The  labor  in  raising  the  crop,  the  expense  of  harvesting 
and  putting  it  upon  the  market,  and  the  profit,  must 
come  out  of  the  difference  between  what  is  paid  and  what 
is  received.  Naturally,  as  the  ratio  between  the  con- 
stituents contained  in  the  products  sold  and  the  price 
received  is  increased,  the  rate  of  income  to  a  unit  of  ex- 
haustion is  increased,  though  in  many  cases  the  increased 
cost  of  the  labor  necessary  is  in  proportion  to  the  increased 
price  received.  This  may  be  illustrated  by  a  comparison 
on  the  fertility  basis  of  the  sale  of  wheat  and  milk.  If 
milk,  which  contains  on  the  average  12  pounds  of  nitro- 
gen, 4|  pounds  of  phosphoric  acid  and  3j  pounds  of 
potash  to  a  ton,  is  sold  for  $1.50  a  hundred  pounds,  the 
nitrogen  is  sold  for  $2  a  pound,  and  the  phosphoric  acid 
and  potash  for,  approximately,  70  cents  a  pound.  In  the 
sale  of  milk  at  this  price,  the  rate  of  income  to  a  unit  of 
exhaustion  is  increased  nearly  four  times  over  that  of  the 
wheat,  though,  because  it  is  in  one  sense  a  manufactured 
product,  the  cost  of  labor  to  a  unit  of  plant-food  con- 
tained is  largely  increased.  Again,  if  cream  is  sold,  the 
prices  received  for  the  constituents  are  still  further  in- 
creased, while  if  the  milk  is  made  into  butter,  and  that 
alone  is  sold,  the  prices  received  measure  the  expenses 
and  profit,  and  the  capital  stock  of  fertility  is  not  materially 
reduced,  though  it  is  in  another  form  and  in  another  place. 

Fertility  content  of  cereals  and  vegetables. 

The  losses  of  the  constituents  in  the  sale  of  cereals 
and  grasses,  corn,  oats,  wheat  and  hay  are,  too,  rela- 
tively greater  than  in  the  sale  of  vegetables  and  fruits,  as 
lettuce,  celery,  potatoes,  tomatoes,  sugar-beets,  apples, 
berries  and  kindred  crops,  though  in  the  case  of  the  latter, 


16 


Fertilizers 


a  higher  degree  of  fertility  is  necessary  in  order  to  pro- 
duce maximum  crops,  and  the  cost  of  production  is  again 
proportionately  greater.  These  facts  strongly  emphasize 
the  necessity  of  a  careful  study  of  the  relation  of  farm 
practice  to  the  artificial  losses  of  fertility. 

The  artificial  loss  of  fertility  that  may  be  incurred  by 
the  sale  of  crops  is  largely  measured  by  the  knowledge  of 
the  producer  concerning  the  relation  between  the  price 
received  for  the  crop  and  the  fertility  contained  in  it, 
and  thus  removed  when  sold,  and  by  his  intelligence  in 
adjusting  his  methods  so  as  to  reduce  to  a  minimum  the 
actual  loss. 

The  following  tabular  statement  shows  very  clearly 
the  differences  in  the  losses  of  the  constituents  in  the  sale 
of  different  classes  of  plants : 

FERTILIZER  CONSTITUENTS  IN  CEREALS  AND  VEGETABLES 


POUNDS  IN  ONE  TON 

Nitrogen 

Phosphoric 
Acid 

Potash 

Cereals  and  Grasses 
Corn      

29.6 
36.2 
34.6 
32.4 
21.6 
20.0 

3.2 

4.4 
5.8 
1.6 
4.8 
5.0 
5.0 

12.2 
15.4 
19.2 
16.2 
7.0 
7.0 

1.8 
3.8 
1.6 
1.0 
1.8 
1.6 
4.0 

7.2 
11.4 
7.0 
10.4 
26.8 
31.4 

9.2 
12.4 
10.2 
8.0 
8.8 
9.0 
15.0 

Oats       

Wheat                      •   -. 

Rve 

Timothy  hay  .... 
Herd  grass      .... 
Vegetables 

Parsnips     .     .     .     .'    . 

Beets  (red)      .     .    ,     . 

Celery   

Natural  Fertility  of  the  Soil  17 

Irrational  farm  practice. 

There  are  methods  of  practice  which  are  entirely  irra- 
tional, and  contribute  to  the  real  losses  of  fertility.  Farm- 
ing is  unprofitable,  not  altogether  because  the  land  is 
exhausted,  but  because  only  those  crops  are  grown  which 
possess  a  high  fertility  value,  and  which  have  a  low  market 
price,  and  thus  the  prices  received  for  the  constituents 
in  the  crop  are  actually  less  than  they  cost  in  land  and 
in  labor ;  and  these  methods  of  practice  are  not  confined 
to  farmers  whose  lands  of  inexhaustible  fertility  have 
been  given  them  by  a  generous  government,  but  are  fol- 
lowed by  farmers  who  annually  purchase  commercial  fer- 
tilizers to  supply  the  losses  of  fertility  thus  sustained. 

Where  the  conditions  are  such  as  to  make  it  imprac- 
ticable to  grow  and  sell  crops,  as  such,  of  a  low  fertility 
value,  the  producer  should  endeavor  to  sell  the  manu- 
factured rather  than  raw  materials,  —  that  is,  to  so  use 
his  crude  products  as  to  lower  the  quantity  of  the  con- 
stituents contained  in  those  sold,  which  explains,  in  part, 
the  greater  success  in  the  long  run  of  a  mixed  husbandry, 
rather  than  single-crop  farming. 

The  artificial  losses  of  our  national  capital  stock  of 
fertility  are,  however,  not  absolute,  if  the  products  are 
consumed  in  our  own  country,  as  more  or  less  of  the  con- 
stituents contained  in  the  crude  products  sold  find  their 
way  back  to  the  farm,  either  in  the  by-products  of  the 
mills,  in  sewage,  in  the  manure  from  cities,  or  in  various 
vegetable  or  animal  wastes ;  but  when  they  are  exported, 
the  loss  is  absolute,  and  the  amounts  so  disposed  of  are  in 
some  degree  a  measure  of  the  rate  of  loss  of  the  capital 
stock  of  fertility  in  our  lands,  though  to  these  must  be 
added  the  losses  due  to  the  improper  use  of  manure  and 
other  waste  materials. 


18  Fertilizers 


Losses  in  manures. 

It  is  natural  to  infer  that  proper  losses  of  fertility  are 
confined  to  the  removal  of  the  constituents  in  the  sale  of 
farm  products,  and  that  those  contained  in  the  materials 
not  sold  and  in  the  feeds  used  upon  the  farm  are  again 
returned  in  part  to  the  land.  Theoretically  this  is  correct, 
but  the  losses  that  do  occur,  particularly  in  the  handling 
of  manures,  should  not  be  overlooked.  While  it  is  im- 
possible to  even  roughly  estimate  the  waste  or  loss  of 
fertility  due  to  the  improper  making  or  handling  of 
manures,  some  idea  may  be  obtained  when  the  enormous 
amounts  produced  and  the  sources  of  possible  loss  are 
considered. 

If  this  enormous  mass  of  waste  material  were  properly 
used,  it  would  go  a  great  way  toward  increasing  the 
present  and  immediate  fertility  of  our  soils,  or  in  retard- 
ing the  time  of  exhaustion,  and  it  is  quite  pertinent  to 
inquire  if  it  is  properly  used.  It  has  been  demonstrated 
by  experiments  at  Cornell  Experiment  Station  that  50 
per  cent  of  the  total  constituents  in  farm  manures  is 
liable  to  be  lost  by  ill-regulated  fermentation  and  by  leach- 
ing; and  further,  careful  observations  and  experiments 
show  that  the  conditions  in  the  larger  number  of  barn- 
yards are  such  as  to  encourage  the  maximum  loss  by 
these  means.  It  is  morally  certain  that  a  large  per- 
centage of  the  constituents  contained  in  them  are  lost; 
they  never  reach  the  right  place  on  the  farm. 

It  is  estimated  that  if  but  one-tenth  of  the  present  waste 
could  be  avoided,  —  and  a  very  large  part  of  it  is  prac- 
tically avoidable,  and  at  a  very  slight  expense,  —  the  total 
amount  of  constituents  that  may  thus  be  saved  for  further 
use  would  be  more  than  equivalent  to  the  amounts  now 


Natural  Fertility  of  the  Soil  19 

purchased  in  the  form  of  commercial  fertilizers.  This 
estimate  is  certainly  conservative,  and  clearly  demon- 
strates the  serious  drain  upon  our  resources  of  fertility  ele- 
ments, due  to  the  lack  of  care  in  the  handling  of  farm 
manures. 

The  conditions,  as  here  pointed  out,  not  only  suggest 
the  need  of  imported  plant-food,  but  that  there  are  oppor- 
tunities for  reducing  this  need  by  careful  saving  and  use 
of  the  constituents  that  are  subject  to  waste. 


CHAPTER  II 

THE  FUNCTION  OF  MANURES  AND  FERTI- 
LIZERS, AND  THE  NEED  OF  ARTIFICIAL 
FERTILIZERS 

WHILE  in  a  broad  sense  a  manure  or  fertilizer  may 
be  regarded  as  anything  that  will  increase  the  yield  of 
a  crop  if  added  to  the  land,  the  chief  function  of  ma- 
nures is  to  furnish  nitrogen,  phosphoric  acid  and  potash. 

THE  ESSENTIAL  ELEMENTS  OF  FERTILIZERS 

These  are  called  the  "essential  manurial  elements," 
or  "constituents,"  to  distinguish  them  from  the  others 
that  are  needed  by  plants,  because  these  three  are  con- 
tained in  the  crops  removed  in  greater  amounts  than 
the  others,  and  because  they  exist  in  the  soil  in  much 
smaller  amounts  than  the  others.  For  example,  culti- 
vable soils  seldom  contain  too  little  iron  or  sulfur,  or 
magnesium.  These  elements  usually  exist  in  quantities 
more  than  sufficient  to  supply  all  the  needs  of  the  plant 
for  them,  and,  because  they  are  required  in  such  exceed- 
ingly small  amounts,  the  soils  are  seldom  exhausted  of 
them.  In  addition  to  this  property  of  supplying  essen- 
tial manurial  constituents,  many  substances  useful  as 
manures  possess,  however,  a  secondary  function :  they 
serve  to  indirectly  increase  the  crop,  but  do  not  add  directly 
to  the  potential  fertility  of  soils. 

20 


The  Function  of  Manures  and  Fertilizers         21 


NATURAL  MANURES  AND  ARTIFICIAL  FERTILIZERS 

Farmyard  manure,  and  many  other  natural  products, 
possess  this  second  function  in  a  marked  degree,  and 
the  indirect  manurial  value  of  these  is  due  largely  to 
the  good  effect  that  the  substances  associated  with  the 
nitrogen,  phosphoric  acid  and  potash  in  them  exert  in 
increasing  the  crop.  This  good  effect  is  observed  in  two 
directions.  First,  the  vegetable  matter  contained  in 
the  natural  manure  improves  the  physical  character  of 
soils  —  those  that  are  clayey  and  compact,  by  making 
them  more  open  and  porous,  separating  the  particles,  so 
that  the  water  and  air  can  penetrate  more  freely,  and 
thus  act  directly  upon  the  dormant  or  insoluble  constit- 
uents that  are  contained  in  it;  and  those  that  are  light 
and  sandy,  by  filling  up  the  open  spaces,  thus  making 
them  more  compact.  In  the  second  place,  the  addition 
of  vegetable  matter  to  soils,  even  though  it  contains  no 
essential  constituents,  improves  it  by  enabling  it  to  more 
readily  and  completely  absorb  and  retain  not  only  the 
water,  but  also  the  soluble  essential  constituents  that 
may  be  added.  The  chief  distinction  between  what  are 
known  as  manures  and  what  are  known  as  fertilizers 
is  the  difference  in  respect  to  this  secondary  function. 
The  manure  possesses  the  two  functions,  the  one  to  supply 
the  essential  constituents,  and  the  other  to  assist  plant 
growth  by  aiding  in  the  improvement  of  those  already 
contained  in  the  soil,  and  this  latter  function  it  exerts  in 
a  marked  degree ;  while  the  fertilizer,  as  a  rule,  possesses 
but  one,  namely,  that  of  furnishing  plant-food.  The 
indirect  effect  of  the  materials  associated  with  the  con- 
stituents in  artificial  fertilizers  is  seldom  very  useful,  and 
sometimes  may  be  harmful. 


22  Fertilizers 


DIRECT  AND  INDIRECT  EFFECT  OF  MANURES 

It  is  obvious,  therefore,  that  any  substance  which  con- 
tains nitrogen,  phosphoric  acid  or  potash  may  serve 
as  a  direct  manure,  and  any  substance  which  contains 
no  plant-food,  but  which  possesses  the  power  of  improv- 
ing the  physical  character  of  soils,  may  also  serve  as  a 
manure,  though  the  one  effect  is  quite  distinct  from  the 
other.  The  first  adds  to  the  soil  the  essential  constitu- 
ents ;  the  other  helps  to  make  the  constituents  already  in 
the  soil  serve  as  food  to  the  plant. 

The  use  of  the  one  will  tend  to  increase  both  the  poten- 
tial and  practical  fertility  in  the  soil,  while  by  the  use  of 
the  other  the  active  fertility  is  increased  as  the  potential 
fertility  is  decreased.  That  is,  when  actual  plant-food 
is  added  in  the  form  of  nitrogen,  phosphoric  acid  or  potash, 
and  crops  are  removed,  the  exhaustion  of  the  soil  is  in 
proportion  to  the  amounts  of  these  removed  over  and 
above  the  amounts  which  have  been  added.  Whereas, 
in  the  other  case,  when  no  plant-food  is  added,  the  exhaus- 
tion is  measured  by  the  amount  of  the  constituents  re- 
moved. It  is  clear,  therefore,  that  the  addition  of  only 
indirect  manures  has  a  tendency  to  rapidly  reduce  the 
fertility  of  soils  of  low  natural  strength,  or  those  that  do 
not  possess  large  stores  of  food  constituents,  whereas, 
on  soils  that  are  rich  in  the  fertility  elements,  the  indirect 
manuring  may  result  in  an  increased  yield  for  a  long 
period,  though  ultimately  the  soil  will  become  exhausted 
—  if  not  completely,  to  such  a  degree  as  to  render  further 
cropping  by  this  method  unprofitable. 

There  are  a  number  of  substances  which  act  in  both 
capacities  —  directly  and  indirectly  —  and  in  order  to 
understand  thoroughly  the  value  of  such  materials  they 


The  Function  of  Manures  and  Fertilizers         23 

must  be  studied  from  both  points  of  view.  Farmyard 
manure  is  an  example.  It  contains  nitrogen,  phosphoric 
acid  and  potash,  and  possesses  the  power  of  improving 
the  physical  character  of  soils.  Lime,  generally  consid- 
ered an  indirect  manure,  may  act  in  the  capacity  of  a 
direct  manure  upon  soils  sufficiently  lacking  in  this  ele- 
ment. Other  materials  which  act  in  both  capacities  under 
peculiar  conditions  are  magnesia  salts,  iron  salts,  basic- 
slag,  nitrate  of  soda  and  the  like. 

UNAVAILABLE  AND  AVAILABLE  PLANT-FOOD 

While,  as  already  stated,  any  material  containing 
either  one  or  all  of  the  three  essential  constituents,  nitro- 
gen, phosphoric  acid  or  potash,  may  serve  as  a  direct 
manure  in  the  sense  that  it  increases  the  potential  fer- 
tility of  any  soil,  the  value  of  the  addition  of  such  mate- 
rials will  depend  not  so  much  on  the  amount,  as  upon 
the  power  that  the  plant  may  possess  of  acquiring  it  — 
and  it  is  here  that  the  difference  between  manures  from 
natural  sources  and  those  from  artificial  sources  is  again 
quite  manifest.  That  is,  the  fertility  constituents  in 
natural  manures  are  in  large  part  combined  with  others 
in  the  form  of  vegetable  matter,  and  with  the  exception 
of  potash,  they  are,  when  in  this  form,  largely  insoluble, 
and,  therefore,  cannot  be  used  by  the  plants  until  after 
decay  begins.  Whereas,  in  artificial  manures,  the  con- 
stituents may  be  not  only  soluble,  but  may  be  in  a  form 
in  which  the  plants  can  take  them  up  immediately. 
In  the  first  case,  the  plant-food  is  said  to  be  unavailable, 
and  in  the  second,  it  is  said  to  be  available. 

Nitrogen,  one  of  the  chief  constituents  of  manures, 
for  example,  exists  in  three  distinct  forms:  (1)  the  or- 


24  Fertilizers 

ganic  form,  in  animal  or  vegetable  matter,  derived  from 
any  form  of  life,  which  must  first  decay  before  it  can  serve 
as  plant-food.  (2)  As  the  decay  goes  on  ammonia  is 
formed,  and  then  (3)  from  the  ammonia  the  nitrate  is 
formed,  which  is  the  form  in  which  plants  take  up  the 
largest  proportion  of  their  nitrogen.  This  process  is  the 
direct  result  of  bacterial  activity  and  is  known  as  nitri- 
fication. Inasmuch  as  products  exist  which  contain 
nitrogen  in  these  three  distinct  forms,  it  is  possible  by  their 
use  to  control  largely  the  feeding  of  the  plant  in  respect 
to  this  element,  while  in  the  case  of  natural  manures, 
the  feeding  of  the  plant  with  nitrogen  depends  upon 
conditions  which  cause  its  change  from  the  organic 
into  the  other  forms.  As  these  conditions  are  variable, 
the  problem  of  the  economical  feeding  of  plants 
with  nitrogen,  other  things  being  equal,  becomes  a  more 
difficult  matter  with  the  natural  than  with  the  artificial 
manures. 

Phosphoric  acid  also  exists  in  different  forms,  the 
form  measuring  to  a  large  degree  its  availability:  the 
organic,  in  which  the  availability  depends  upon  the 
rapidity  of  decay;  and  the  soluble  and  immediately 
available  form,  —  that  is,  the  form  that  distributes 
everywhere,  and  which  the  plant  can  absorb  immedi- 
ately it  comes  in  contact  with  the  roots.  Commercial 
products  exist  which  contain  the  phosphoric  acid  in  these 
distinct  forms.  The  user  is  therefore  enabled  to  supply 
this  constituent  in  such  form  as  may  best  suit  his  crop  and 
soil  conditions. 

In  the  case  of  potash,  distinct  forms,  as  muriate,  sul- 
fate  and  carbonate,  also  exist,  though  in  the  case  of  potash, 
the  form  in  which  it  is  combined  exerts  less  influence 
upon  the  availability  of  the  element  to  the  plant  than  is 


The  Function  of  Manures  and  Fertilizers         25 

the  case  with  nitrogen  and  phosphoric  acid.    All  of  these 
forms  are  soluble,  and  can  be  readily  absorbed. 

DANGER  OF  LOSS  FROM  THE  USE  OF  SOLUBLE  PLANT-FOOD 

The  fact  that  the  artificial  fertilizer-products  con- 
tain the  constituents  in  such  forms  and  combinations 
as  to  enable  them  to  feed  the  plant  immediately,  also 
presents  some  disadvantages  from  the  standpoint  of 
economical  use.  This  is  particularly  true  in  the  case 
of  nitrogen,  for  nitrogen,  when  applied  in  the  form  of 
nitrate,  in  which  form  it  is  taken  up  by  the  plant,  does 
not  combine  to  make  insoluble  compounds,  but  remains 
freely  soluble.  A  great  waste,  therefore,  may  ensue  from 
leaching  into  the  lower  layers  of  the  soil  and  beyond  the 
roots  of  plants,  or  into  the  drains,  and  the  plant-food  be 
carried  away,  unless  care  is  exercised  both  as  to  the  amount 
and  the  method  of  application.  With  soluble  phosphates, 
the  danger  of  loss  is  much  less  than  with  nitrogen.  If 
these  are  applied  in  too  large  quantities  to  meet  the  needs 
of  the  plants,  or  under  improper  conditions,  their  tend- 
ency is  not  to  remain  soluble,  but  to  revert  to  their 
original  and  insoluble  form.  The  main  fact,  however, 
is  that  in  artificial  fertilizers  we  may  have  the  constit- 
uents in  distinct  and  separate  forms,  which  permits  the 
feeding  of  the  plant,  rather  than  the  feeding  of  the  soil ; 
and  this  is  usually,  and  must  necessarily  be,  the  case  when 
natural  manure  products  serve  as  the  entire,  source  of  the 
added  fertility.  For  example,  nitrogen  may  be  supplied 
in  artificial  fertilizers  in  three  forms,  each  form  being  dis- 
tinct and  separate  from  the  other,  and  each  giving  up  its  ni- 
trogen to  the  plant  at  a  different  time,  supplying  its  needs  as 
required  by  growth,  in  which  case  the  danger  of  loss  is  small. 


26  Fertilizers 

THE    USEFULNESS    OF    A    FERTILIZER   CONSTITUENT    DOES 
NOT  DEPEND  UPON  ITS  ORIGINAL  SOURCE 

It  should  be  remembered,  too,  that  artificial  manures 
or  fertilizers  supply  plant-food  just  as  well  as  other  and 
more  common  products.  The  fact  that  the  food  exists 
in  substances  other  than  those  which  are  familiar  to  the 
farmer,  is  no  evidence  that  it  may  not  be  quite  as  good, 
or  even  better,  than  when  contained  in  his  home-made 
products.  It  is  not  the  outward  appearance  of  a  sub- 
stance, but  the  kind  and  form  of  the  elements  contained 
in  it,  that  measures  its  value  as  a  fertilizer. 

For  example,  the  nitrogen  that  may  be  applied  in 
the  form  of  a  commercial  fertilizer  exerts  no  different 
function  in  the  plant  than  that  which  may  be  acquired 
from  the  original  soil,  or  from  materials  that  have  recently 
been  obtained  from  that  soil,  and  again  returned  as  yard 
manure.  The  same  is  true  of  phosphoric  acid  and 
potash.  In  their  concentrated,  artificial  forms,  they  serve 
to  feed  the  plants  in  exactly  the  same  way,  and  exert  the 
same  function  in  them,  as  those  contained  in  the  soils 
themselves,  or  that  may  be  contained  in  wood  ashes,  or 
materials  more  familiar,  or  of  more  common  occurrence. 
The  form  in  which  they  exist  when  applied  does  not 
necessarily  imply  that  they  are  stimulants  rather  than 
food,  though  frequently,  because  of  their  form,  the  plants 
are  able  to  absorb  them  more  readily,  and  thus  by  their 
rapidly  increased  growth,  encourage  a  belief  that  an  un- 
due stimulating  effect  accompanies  their  use.  The  fa- 
mous experiments  of  Lawes  and  Gilbert,  at  Rothamsted, 
England,  teach  this  one  thing  very  emphatically;  viz., 
the  efficiency  of  chemical  fertilizers  as  compared  with 
yard  manures. 


The  Function  of  Manures  and  Fertilizers         27 


USE  OF  FERTILIZERS 

While  manures  in  the  ordinary  sense,  and  even  mate- 
rials which  are  now  included  under  the  head  of  artificial 
manures,  such  as  ground  bone  and  wood  ashes,  have  been 
used  for  a  very  long  tune,  the  use  of  artificial  products 
in  a  true  sense  is  of  comparatively  recent  origin.  The 
first  use  of  genuine  artificial  fertilizers  dates  from  the  pub- 
lication of  Baron  von  Liebig's  book,  "Organic  Chemistry 
in  its  Application  to  Agriculture  and  Physiology,"  in 
1840 ;  yet  for  a  long  time  after  this  date  the  increase  in 
their  use  was  very  gradual.  The  very  excellent,  and  at 
that  time  surprising,  results  which  were  obtained  from 
the  application  of  Peruvian  guano,  one  of  the  first  prod- 
ucts to  receive  attention,  manifestly  increased  the 
interest  in  the  subject  also.  These  good  results  were 
observed  more  particularly  on  the  continent  of  Europe, 
where  the  lands  had  been  under  cultivation  for  a  long 
tune.  The  use  in  America,  previous  to  1860,  was  quite 
insignificant.  Since  the  work  of  Liebig,  a  very  great 
amount  of  study  has  been  given  to  the  subject,  both  in 
reference  to  the  essential  character  of  the  various  mate- 
rials, and  their  influence  upon  the  production  of  plants. 
Perhaps  no  other  single  subject  relating  to  agricultural 
science  has  been  studied  more  fully  than  the  question  of  * 
the  use  of  artificial  manures;  and  these  studies  have 
resulted,  not  only  in  the  discovery  of  new  materials,  but 
in  their  better  preparation  for  use  as  plant-food,  which 
greatly  increased  their  effective  use.  There  is  no  ques- 
tion connected  with  agriculture  which  is  of  greater  direct 
and  practical  importance,  particularly  in  those  countries 
which  have  been  depleted  of  their  active  fertility  by  the 
means  mentioned,  or  in  which  the  conditions  are  as  pre- 


28  Fertilizers 

viously  outlined,  than  definite  knowledge  of  the  true 
principles  which  govern  in  the  profitable  use  of  com- 
mercial fertilizers.  Yet,  notwithstanding  all  the  good 
results  thus  obtained,  and  their  great  practical  importance 
to  agriculture,  much  still  remains  to  be  done,  particu- 
larly in  the  establishment  of  fundamental  principles. 

While  it  is  desirable  that  in  a  work  of  this  kind  scien- 
tific discussions  should  be  avoided  as  far  as  possible,  and 
the  subject  made  as  plain  as  is  practicable  to  those  using 
fertilizers,  it  is  necessary  to  their  right  use  that  those  who 
apply  them  to  their  land  should  have  a  very  clear  concep- 
tion of  the  underlying  principles,  so  far  as  they  are  known, 
in  order  that  they  may  intelligently  increase  their  pro- 
duction, and  thus  reap  a  profit.  Definite  knowledge  is 
an  important  factor  in  determining  their  profitable  use. 

THE  NEED  OF  ARTIFICIAL  FERTILIZERS 

The  considerations  in  the  previous  chapter  explained 
in  part,  and  in  a  broad,  general  way,  the  necessity  for  the 
use  of  commercial  fertilizers.  The  conditions  of  farming 
in  this  country  have  greatly  changed  in  the  past  thirty 
years,  and  these  changes  have,  perhaps,  a  still  more 
important  bearing  in  showing  the  need  of  imported  fer- 
tility than  the  conditions  already  discussed.  The  first 
direction  in  which  important  changes  have  taken  place 
is  in  the  increased  cost  of  farm  labor  and  in  the  relatively 
low  prices  now  received  for  the  staple  crops,  the  cereal 
grains,  cotton  and  tobacco. 

The  cost  of  production  to  a  unit  of  income  is  increased. 

The  cost  of  labor  is  increased  because  proportion- 
ately higher  wages  are  now  paid,  and  because  the  labor 


The  Ifanction  of  Manures  and  Fertilizers         29 

now  obtainable  is  on  the  whole  less  efficient,  being  per- 
formed more  largely  by  those  untrained  for  their  work, 
rather  than  by  the  owner  and  his  sons;  and  this  in- 
creased cost  of  labor  makes  the  cost  of  growing  the  staple 
crops  much  greater  in  proportion  to  their  market  value 
than  was  formerly  the  case,  though  there  are,  of  course, 
exceptions. 

For  example,  harvest  wages  throughout  the  eastern 
part  of  the  country,  at  any  rate,  were  in  the  sixties  regu- 
lated somewhat  by  the  price  of  wheat.  When  wheat  was 
$3  a  bushel  in  the  eastern  states,  the  daily  wage  was  $3. 
Now  the  daily  wage  in  the  east  ranges  from  $2  to  $2.50  a 
day,  while  the  price  of  wheat  does  not  often  exceed  $1  a 
bushel,  and  the  price  received  is  frequently  much  lower.. 
The  wages  for  other  kinds  of  farm  work  are  proportion- 
ately the  same  in  reference  to  present  prices  of  products. 
During  the  past  twenty-five  years  the  cost  of  labor  has 
increased  materially  and  remains  constant  regardless  of 
the  nature  of  the  work,  character  of  farming,  crop  grown 
or  season.  This  condition,  considered  in  connection 
with  the  important  fact  that  the  total  cost  of  crop  to  the 
acre  is  practically  the  same,  whether  the  yield  is  high  or 
low,  exerts  a  decided  influence  in  determining  profits, 
particularly  on  land  of  medium  fertility.  The  cost  of 
preparing  the  land  for  the  seed,  the  cost  of  seed  and  the 
seeding  and  harvesting  are  the  same  for  a  crop  of  wheat, 
whether  the  yield  is  10  or  30  bushels  an  acre;  but  this 
cost  will  not  permit  a  profit  from  the  10-bushel  yield, 
because  the  cost  to  the  bushel  is  too  largely  increased. 
The  same  considerations  hold  true  for  a  number  of  other 
crops.  Small  yields  of  these  relatively  low-priced  crops 
cannot  be  profitably  produced  with  the  present  high  price 
of  labor;  and  it  has  been  shown,  furthermore,  that  land 


30  Fertilizers 

which  is  not  in  a  high  state  of  fertility  will  not  produce 
large  yields. 

Many  soils,  especially  those  in  the  eastern  and  south- 
ern sections  of  our  country,  which  were  not  originally 
very  fertile,  and  which  have  been  cropped  for  a  long 
tune,  show  abundant  evidence  of  the  need  of  fertility  from 
sources  outside  of  the  farm,  in  order  that  maximum  crops 
may  be  produced.  The  aim  should  be,  therefore,  to  make 
the  conditions  of  soil  better,  and,  if  possible,  so  perfect 
as  to  guarantee  against  any  lack  of  food  during  the  grow- 
ing period,  and  thus  make  the  conditions  of  climate  and 
season,  rather  than  the  soil,  the  measure  of  the  crop. 
That  is,  as  far  as  practicable,  the  yield  that  it  is  possible 
to  obtain  in  a  given  locality  should  be  the  aim  of  the 
farmers  in  that  locality.  In  order  to  make  the  conditions 
of  soil  perfect  in  this  respect,  the  fertility  elements  must  be 
added,  though  indirect  manuring,  in  the  form  of  better 
cultivation  and  better  use  of  the  waste  products  of  the 
farm,  are  also  to  be  encouraged. 

A  greater  demand  for  special  crops. 

In  the  second  place,  farming  to-day  consists  of  much 
more  than  the  simple  production  of  the  staple  crops. 
Changed  conditions  are  shown  very  clearly  in  the  increased 
demand  for  medicinal  plants,  nuts,  nursery  stock,  mar- 
ket-garden products,  fruits,  and  special  poultry,  dairy  and 
swine  products.  Not  so  many  years  ago  the  staple 
crops  already  described  were  practically  the  only  ones 
raised  and  sold  from  the  farm. 

For  example,  the  growing  of  vegetables  and  fruits 
was  limited.  They  were  regarded  as  luxuries,  and  the 
area  given  to  them  was,  on  most  farms,  only  sufficient 
to  meet  the  needs  of  the  home.  These  were  not  regarded 


The  Function  of  Manures  and  Fertilizers         31 

as  crops  in  the  same  light  as  the  others,  and  were  seldom 
the  source  of  direct  income.  At  the  present  time,  vege- 
tables and  fruits  are  regarded  as  necessities  in  every  home, 
and  their  use  is  not  confined  to  the  season  in  which  they 
can  be  provided  in  the  immediate  vicinity  of  the  cities 
or  towns  where  they  are  used ;  they  are  drawn  from  points 
far  distant,  and  the  demand  is  such  as  to  require  the  use 
of  wide  areas  in  order  to  supply  the  needs.  The  growing 
of  market-garden  crops  and  fruits  is  now  the  basis  of 
specific  agricultural  industries  which  have  assumed  large 
proportions. 

Much  progress  has  been  made,  too,  in  the  develop- 
ment of  methods  of  practice  in  these  lines  of  farming, 
and  the  experience  gathered  has  shown  that  even  our 
most  fertile  soils  in  their  natural  conditions  contain 
too  little  active  food  to  insure  maximum  yields  of  crops 
of  the  best  quality;  in  these  lines  of  farming,  too,  earli- 
ness  and  edible  quality  of  products,  which  are  influenced 
by  the  food  supply,  are  important  factors  in  determining 
the  profits  to  be  derived.  The  areas  now  necessarily 
devoted  to  these  crops  are  so  great  that  soils  of  a  high 
natural  fertility,  even  if  natural  fertility  alone  could  be 
depended  upon,  are  too  limited  to  meet  the  demand  and 
enable  a  profit,  especially  in  the  vicinity  of  good  markets  ; 
in  other  respects  a  good  location,  because  permitting  of 
cheap  distribution,  is  an  important  factor. 

Farm  manures  are  inadequate. 

Farm  manures  might  meet  the  needs  for  the  staple 
crops,  as  they  are  well  adapted  in  many  respects  for 
the  purpose,  but,  under  present  systems  of  manage- 
ment, the  amount  is  not  sufficient  to  meet  the  annual 
losses  from  the  sale  of  crops,  much  less  to  provide  an 


32  Fertilizers 

increase,  and  the  only  other  source  is  an  artificial  supply, 
or  commercial  fertilizers.  For  the  special  crops  already 
described,  the  natural  manures  of  both  farm  and  city 
are  not  only  not  sufficient,  but,  because  of  their  character 
and  composition,  are  not  well  adapted  to  meet  economi- 
cally the  entire  demands  of  the  plants.  In  the  first  place, 
they  are  bulky,  and  thus  expensive  to  handle.  In  the 
second  place,  the  fertility  elements  contained  in  them  are 
not  in  good  proportion;  they  are,  as  a  rule,  poor  in  the 
mineral  elements  and  rich  in  nitrogen,  and  their  use  in 
sufficient  amounts  to  meet  the  needs  of  the  plant  for  the 
mineral  elements  results  in  a  waste  of  the  nitrogen.  Third, 
the  constituents  contained  in  them  are  not  in  sufficiently 
active  forms  to  provide  for  a  rapid  and  continuous  growth 
without  an  excessive  application,  which  frequently  results 
in  a  serious  waste  not  only  of  the  nitrogen,  as  already  indi- 
cated, but,  in  the  case  of  many  crops,  an  abnormal  growth 
of  vine  or  stalks,  which  may  seriously  injure  the  market- 
able quality  of  the  crops.  For  many  crops,  economical 
production  requires  that  the  natural  manures  be  supple- 
mented by  artificial  supplies,  by  means  of  which  the  form 
and  amount  of  the  individual  constituent  can  be  regu- 
lated to  meet  the  needs  of  the  various  plants. 

The  growing  importance  of  fruit-growing. 

In  fruit-culture,  an  industry  of  growing  importance, 
it  has  been  found  that  soils  in  their  natural  condition, 
while  they  may  be  well  adapted  in  other  respects,  —  that 
is,  possess  a  suitable  physical  character  for  the  growth 
of  this  class  of  crops,  —  contain  insufficient  amounts  of 
the  mineral  constituents  which  are  required  in  order 
that  continuous  and  large  crops  of  perfect  fruit  may 
be  secured.  To  supply  this  deficiency  farmyard  manure 


The  Function  of  Manures  and  Fertilizers         33 

would  cause  in  many  cases  an  over-supply  of  vegetable 
matter  containing  nitrogen,  which  for  these  crops  is  fre- 
quently followed  by  disastrous  results,  not  only  causing 
an  abnormal  growth  of  leaf  and  wood,  but  inducing  it  at 
such  periods  of  the  year  as  to  materially  interfere  with  the 
proper  ripening  of  both  the  wood  and  the  fruit.  By  the 
use  of  artificial  fertilizers,  these  difficulties  may  be  largely 
overcome. 

WILL  IT  PAY  TO  USE  FERTILIZERS? 

It  must  be  confessed  that  to  give  a  definite  and  positive 
answer  to  this  question,  with  our  present  state  of  knowl- 
edge, is  a  difficult  matter,  if  not  well-nigh  impossible, 
because  of  the  very  large  number  of  varying  conditions 
that  are  involved. 

Usually  such  a  question  cannot  be  answered  in  a 
rational  way  without  first  securing  definite  information 
concerning  the  conditions  under  which  they  are  to  be 
applied,  as,  for  instance,  the  character  of  soil,  whether 
a  sand,  clay  or  loam;  situation  in  reference  to  mois- 
ture, whether  too  dry  or  too  wet;  the  kind  of  subsoil, 
whether  a  loose,  open  sand  or  gravel,  a  medium  clay  or 
a  tight,  impervious  hard-pan;  the  character  of  the  pre- 
vious treatment  and  cropping,  whether  the  land  has  been 
manured  or  fertilized,  whether  good  cultivation  has  been 
practiced,  whether  leguminous  crops  have  been  grown  to 
any  extent,  whether  the  produce  raised  has  been  sold, 
or  fed  on  the  land ;  whether  the  object  of  the  growth  has 
been  for  immature  produce  and  for  early  market,  and 
artificial  growth  demanded,  or  whether  for  maturity, 
when  the  natural  tendency  has  simply  been  assisted  and 
the  development  normal  in  all  directions. 


34  Fertilizers 

If  these  questions  are  answered  truthfully  and  in 
detail,  a  scheme  of  fertilization  may  be  adopted  that 
will  enable  the  farmer  to  secure  the  greatest  returns  for 
the  plant-food  applied. 

That  the  returns  from  the  use  of  fertilizers  are  fre- 
quently unprofitable  is  not  always  the  fault  of  the  fer- 
tilizer, and  this  point  may  be  illustrated  by  the  following 
typical  case:  One  farmer  applies  plant-food,  his  crop  is 
doubled  or  trebled,  and  a  reasonable  profit  is  secured. 
Another  farmer  applies  the  same  amount  and  kind  of 
fertilizer  under  similar  natural  conditions  of  soil,  and  he 
receives  no  benefit.  The  same  climatic  conditions  sur- 
rounded the  crops  of  both :  the  sun  that  warmed  the  soil 
and  furnished  the  energy  necessary  for  the  production  of 
the  largely  increased  crop  is  the  same  sun  that  shone  upon 
the  small  crop ;  the  air  that  furnished  a  large  proportion 
of  the  food  for  the  one  is  the  same  air  that  surrounded 
the  other;  the  rains  that  moistened  and  assisted  in  the 
solution  and  circulation  of  plant-food  for  the  one  were 
the  same  for  the  other.  Why,  then,  the  difference  in 
results?  In  one  case  the  natural  agencies,  sun,  air, 
and  water,  were  assisted  and  enabled  to  do  their  maximum 
work,  while  in  the  other,  they  were  prevented  from  exer- 
cising their  full  influence.  Physical  conditions  of  soil 
were  imperfect,  due  to  careless  plowing,  seeding,  cultiva- 
tion and  cropping. 

In  other  words,  the  profit  from  the  use  of  plant-food 
is  measured  to  a  large  degree  by  the  perfection  of  soil 
conditions,  which  are  entirely  within  the  power  of  the 
farmer  to  control.  The  production  possible  from  a  defi- 
nite amount  of  plant-food  can  be  secured  only  when  the 
conditions  are  such  as  to  permit  its  proper  solution, 
distribution  and  retention  by  the  soil. 


The  Function  of  Manures  and  Fertilizers         35 

The  fact  that  fertilizers  may  now  be  easily  secured, 
and  the  ease  of  application,  have  encouraged  a  careless 
use,  rather  than  a  thoughtful  expenditure,  of  an  equivalent 
amount  of  money  or  energy  in  the  proper  preparation  of 
the  soil.  Of  course,  it  does  not  follow  that  no  returns 
are  secured  from  plant-food  applied  under  unfavorable 
conditions,  though  full  returns  cannot  be  secured  under 
such  circumstances.  Good  plant-food  is  wasted,  and  the 
profit  possible  to  be  derived  is  largely  reduced. 

Again,  because  farming,  in  its  strict  sense,  is  the 
conversion  of  three  essential  elements  into  salable  prod- 
ucts, the  time  to  apply  plant-food  must  be  governed 
largely  by  its  cost  and  the  kind  of  crop  upon  which  it 
is  applied. 


CHAPTER  III 
NITROGENOUS  FERTILIZERS 

NITROGEN  is  the  most  expensive  constituent  of  fertilizers, 
and,  all  things  considered,  it  is  one  of  the  most  useful. 
Nitrogen  exists  in  nature  as  a  component  of  the  air,  and 
though  quite  as  necessary  to  vegetation  as  carbon  or 
oxygen,  —  which  also  exist  in  the  atmosphere,  and  which 
are  readily  acquired  by  all  plants,  —  all  plants  do  not 
have  the  power  of  acquiring  nitrogen  from  this  source. 
This  power  seems  to  be  limited  to  a  class  of  plants  called 
Leguminosse,  to  which  belong  the  various  clovers,  peas, 
beans,  vetches  and  a  number  of  others.  The  important 
farm  crops  belonging  to  the  other  botanical  groups  of  plants 
obtain  their  nitrogen  largely,  if  not  altogether,  from  the  soil. 

Vegetable  or  animal  matter  containing  nitrogen  may 
serve  as  a  source  of  nitrogen  to  plants,  though  it  cannot 
feed  them  with  this  element  to  any  extent  until  it  decays 
or  rots.  In  order  to  obtain  a  clear  conception  of  the  use 
of  nitrogen  as  a  fertilizer,  one  should  understand  the  need 
of  plants  for  it,  what  is  meant  by  form  of  nitrogen,  and  the 
sources  from  which  the  various  forms  may  be  derived, 
as  well  as  the  relative  agricultural  or  crop-producing  value 
of  the  nitrogen  in  existing  commercial  forms. 

WHAT  IS  MEANT  BY  FORM   OF  NITROGEN? 

Strictly  speaking,  form  of  nitrogen  has  reference  to  its 
combination  or  association  with  other  chemical  elements, 
though  sometimes  the  term  "  form  "  is  used  to  indicate  rate 

36 


Nitrogenous  Fertilizers  37 

of  solubility,  which  also  measures  to  some  degree  avail- 
ability, since  it  happens  that  soluble  forms  of  nitrogen 
are  really  more  available  than  the  insoluble  forms,  though 
neither  the  soluble  nor  insoluble  forms  show  the  same  rate 
of  availability ;  that  is,  a  pound  of  soluble  nitrogen  is  not 
equally  available  from  whatever  source  derived,  and  a 
pound  of  insoluble  from  one  source  may  be  much  more 
available  than  a  pound  from  another.  The  form  in  which 
nitrogen  exists  in  vegetable  and  animal  matter  is  called 
the  "organic  form,"  because  it  is  associated  with  other 
constituents,  as  carbon,  hydrogen  and  oxygen,  which  are 
necessary  to  make  the  substances  that  constitute  animal 
or  vegetable  matter.  The  term  "organic,"  as  applied  to 
nitrogen,  covers  a  whole  series  of  substances,  and  does 
not  indicate  a  uniformity,  either  in  content  or  quality  of 
the  nitrogen,  as  is  the  case  with  distinct  chemical  com- 
pounds; hence,  associated  with  the  knowledge  of  form 
of  nitrogen,  when  it  exists  in  organic  products,  must  be  a 
knowledge  of  whether  the  material  contains  a  very  con- 
siderable amount  of  nitrogen,  and  whether  it  is  likely  to 
be  readily  changed,  and  thus  become  available  as  food  for 
plants. 

Any  nitrogenous  vegetable  or  animal  matter  may  serve 
as  a  fertilizer,  though  organic  nitrogen  in  commercial  fer- 
tilizers is  usually  obtained  from  products  relatively  rich 
in  this  constituent,  and  it  is  only  these  that  can  be  used 
to  advantage  in  making  what  are  known  as  "high-grade 
fertilizers."  The  leading  animal  substances  of  this  class 
are  now  mentioned. 

DRIED  BLOOD 

One  of  the  most  important  products  from  which  organic 
nitrogen  is  derived  for  commercial  fertilizers  is  dried  blood. 


38  Fertilizers 

It  is  important  not  because  the  supply  is  large  and  the 
price  low,  but  because  it  is  one  of  the  most  concentrated, 
one  of  the  richest  in  nitrogen  of  the  organic  nitrogenous 
fertilizing  materials.  It  is  one  of  the  best,  since  its  physi- 
cal character  is  such  as  to  permit  of  its  very  rapid  decay 
in  the  soil  during  the  growing  season.  This  tendency  to 
decay  rapidly  is  plainly  apparent,  when  it  is  remembered 
that  blood  as  it  exists  in  the  animal  is  in  fluid  form,  and 
naturally  any  material  which  is  sufficiently  finely  divided 
to  permit  of  its  ready  flow,  and  is  not  associated  with  any 
hard  or  fibrous  material,  possesses  characteristics  which 
enable  a  rapid  breaking  down  when  subjected  to  the 
proper  temperature  and  moisture  conditions  which 
promote  decay. 

Dried  blood  for  fertilizing  purposes  is  chiefly  obtained 
from  the  large  slaughtering  establishments.  The  markets 
recognize  two  distinct  kinds,  red  and  black.  The  former 
is  carefully  dried  with  hot  water  and  contains  13  to  14 
per  cent  of  nitrogen.  It  is  uniform  in  composition  and 
because  of  its  quality  commands  the  higher  price.  It 
contains  only  traces  of  phosphoric  acid.  The  market  prod- 
uct is  standardized  and  guaranteed  to  contain  16  per 
cent  ammonia.  The  latter  —  black  blood  —  is  dried  at  a 
higher  temperature  with  less  care,  which  gives  it  a  darker 
color  and  leathery  character.  It  also  contains  consider- 
able impurities,  such  as  bone.  It  contains  from  6  to  10 
per  cent  of  nitrogen  and  often  as  high  as  4  per  cent  of 
phosphoric  acid.  In  this  case,  also,  the  market  product 
is  standardized  and  guaranteed  to  contain  12  per  cent  of 
ammonia. 

The  red  blood  is  considered  a  high-grade  fertilizer 
material,  uniform  in  composition,  high  in  nitrogen  and 
of  excellent  mechanical  texture.  The  black  blood,  while 


Nitrogenous  Fertilizers  39 

considered  better  than  many  other  organic  nitrogenous 
materials,  is  less  concentrated  and  less  uniform.  It  is  un- 
fortunate from  the  farmer's  point  of  view  that  the  supply 
of  these  materials  is  decreasing  so  rapidly. 

DRIED    MEAT     OR    MEAL,    AZOTIN,    AMMONITE    OR    ANIMAL 

MATTER 

Dried  meat  or  meal,  azotin,  ammonite  or  animal  matter, 
are  terms  applied  to  practically  the  same  product  produced 
at  rendering  establishments,  where  the  different  portions  of 
dead  animals  are  utilized.  These  are  subjected  to  treat- 
ment, usually  dried  and  extracted  with  steam,  for  the 
purpose  of  securing  the  fat,  though  formerly,  and  even 
now,  a  large  portion  of  this  product  is  obtained  from  the 
beef  extract  factories.  When  relatively  pure  it  contains 
13  to  14  per  cent  of  nitrogen  and  compares  favorably  with 
blood.  When  the  use  of  fertilizer  was  less  and  the  supply 
relatively  greater  this  was  an  important  product.  To- 
day it  is  seldom  heard  of  and  the  market  does  not  recognize 
it  as  such. 

This  product,  very  limited  in  supply,  is  reasonably  uni- 
form in  composition,  containing  as  high  as  12  per  cent  of 
nitrogen,  and  ranks  among  the  high-grade  materials. 
It  is  considered  superior  to  leather,  wool  or  hair. 

DRIED  AND  GROUND  FISH,   OR  FISH  GUANO 

Ground  fish  is  obtained  from  two  sources:  first,  from 
the  offal,  largely  bones  and  skins,  of  fish  packing  or  canning 
houses ;  and  second,  from  the  fish  pomace  resulting  from 
extraction  of  the  oil  from  the  Menhaden.  The  latter 
product  is  richer  in  nitrogen  and  is  more  uniform  in  char- 
acter than  the  wastes  from  the  packing  houses.  Dried 


40  Fertilizers 

ground  fish  from  this  source  contains  from  7  to  8  per  cent 
of  nitrogen,  and  from  6  to  8  per  cent  of  phosphoric  acid. 
The  former,  owing  to  the  varying  proportions  of  bone, 
skin  and  flesh  contained  in  it,  varies  widely  in  its  content  of 
nitrogen.  Fish,  besides  affording  a  considerable  supply  of 
nitrogen,  is  also  regarded  as  a  good  source  of  this  element, 
ranking  in  availability  well  up  to  blood. 

The  use  of  these  materials  is  more  common  along  the 
coast,  where  fishing  is  an  important  industry.  The  supply 
of  fish  pomace  is  to  a  marked  degree  regulated  by  the 
abundance  of  Menhaden,  which  varies  greatly  from  year 
to  year.  More  profitable  use  may  be  made  of  these  prod^ 
ucts  if  applied  a  few  days  before  planting  upon  soils 
which  present  conditions  favorable  to  decomposition. 

TANKAGE 

Tankage  is  a  highly  nitrogenous  product,  and  consists 
chiefly  of  the  dried  animal  wastes  from  the  large  abattoirs 
and  slaughtering  establishments.  It  is  variable  in  its 
composition,  since  it  includes  the  otherwise  unusable 
parts  of  the  carcass,  as  bone,  tendons,  flesh,  hair  and  the 
like.  The  portions  of  this  from  the  different  animals  not 
only  vary  in  their  composition,  but  they  are  used  in  vary- 
ing proportions,  which  naturally  results  in  an  extremely 
variable  product.  What  is  known  as  "concentrated 
tankage,"  which  is  obtained  by  evaporating  the  fluids 
which  contain  certain  extractive  animal  matter,  is  the 
richest  in  nitrogen,  and  is  more  uniform  in  character  than 
the  others;  and  because  of  its  fineness  of  division  and 
physical  character,  the  nitrogen  contained  in  it  is  also  more 
active  than  in  the  other  forms.  Two  distinct  kinds  of 
tankage  can,  therefore,  be  obtained :  first,  concentrated 


Nitrogenous  Fertilizers 


41 


tankage,  which  is  the  richer  in  nitrogen,  ranging  from  10 
to  12  per  cent,  and  which  contains  very  little  phosphoric 
acid;  and  second,  crushed  tankage,  which  is  of  several 
grades,  ranging  from  4  to  9  per  cent  nitrogen,  and  from 
3  to  12  per  cent  of  phosphoric  acid.  Products  are  some- 
times sold  as  tankage,  which  contain  much  more  than  the 
maximum  of  phosphoric  acid  and  less  than  the  minimum 
of  nitrogen  here  given,  in  which  case  they  are  to  be  classed 
with  bone,  rather  than  with  tankage.  Tankage  varies 
so  much,  both  in  its  content  of  phosphoric  acid  and  nitro- 
gen, that  in  the  trade  it  is  always  sold  on  the  basis  of  its 
composition.  The  percentage  of  nitrogen  and  phosphoric 
acid  is  distinctly  stated,  and  because  it  contains  very  con- 
siderable amounts  of  phosphoric  acid,  its  commercial  value 
is  not  wholly  based  on  its  content  of  nitrogen,  as  is  the  case 
with  dried  blood,  dried  meat  and  concentrated  tankage. 
The  market  recognizes  several  distinct  grades  indicated 
by  the  following  guarantees : 


PERCENT- 

PERCENTAGE 
OF  AMMONIA 

PERCENT  AGE  OF  B. 

P.  OF  L. 

PERCENT- 
AGE OF 
NITROGEN 

AGE  OF 
PHOS- 
PHORIC 

ACID 

11 

20 

equivalent 

to 

9.0 

9.15 

9 

20 

equivalent 

to 

7.4 

9.15 

7 

30 

equivalent 

to 

5.8 

13.75 

7 

15 

equivalent 

to 

5.8 

6.80 

Care  should  be  taken  in  the  purchase  of  tankage  be- 
cause it  is  sometimes  mixed  with  garbage  tankage,  a 
material  less  valuable  and  more  variable.  Adulterations 
of  this  kind  are  not  easily  detected.  They  are  more 
common  in  the  less  concentrated  tankage  products. 


42  Fertilizers 


GARBAGE  TANKAGE 

While  this  material  is  considered  a  low-grade  product, 
it  is,  nevertheless,  important  because  the  supply  is  in- 
creasing annually.  It  is  manufactured  from  kitchen 
wastes  of  the  cities,  sometimes  by  drying,  sometimes  by 
partial  charring,  but  more  often  it  is  a  by-product  after 
treatment  to  extract  oils  and  greases.  However  derived, 
it  is  very  variable  in  composition  and  its  value  as  a  fer- 
tilizer differs  with  its  content  of  the  elements  of  plant-food. 
It  is  now  used  to  considerable  extent  in  the  manufacture 
of  commercial  fertilizers  and  sometimes  as  an  absorbent 
in  stables,  but  for  this  purpose  it  lacks  the  desired  qual- 
ity of  cleanliness  and  often  carries  disagreeable  odors. 
Analyses  show  that  it  may  contain  as  high  as  2.5  to  3 
per  cent  of  nitrogen,  1.5  to  3  per  cent  of  phosphoric  acid 
and  .75  to  1.5  per  cent  of  potash. 

LOW-GRADE  NITROGENOUS  PRODUCTS 

Other  products  which  contain  a  high  content  of  nitrogen 
are  frequently  used.  These,  because  of  their  low  rate  of 
availability,  constitute  a  separate  and  distinct  class. 

Horn  meal,  or  ground  horn,  is  reasonably  uniform  in  its 
composition  or  content  of  nitrogen.  It  contains  as  high 
as  10  or  12  per  cent  of  nitrogen,  but  it  is  slow  to  decay 
when  used  in  its  natural  state,  and,  therefore,  is  not  re- 
garded as  an  economical  source  of  this  element,  unless 
it  can  be  obtained  at  a  low  price. 

Leather  meal  is  another  product  which  is  rich  in  nitrogen, 
but  which  is  so  slow  to  decay  that  its  use  in  the  natural 
state  is  not  recommended.  One  object  in  making  leather 
is  to  render  it  resistant  to  the  conditions  which  promote 


Nitrogenous  Fertilizers  43 

decay,  and  ground  leather  may  remain  for  years  in  the 
soil  in  an  unchanged  condition. 

Wool  and  hair  waste  are  also  products  which  exist  in 
considerable  quantities,  and  while  variable  in  composi- 
tion, are  frequently  rich  in  nitrogen,  but  they  are  classed 
with  leather  because  of  their  slow  activity.  Their  me- 
chanical form,  coarse  and  bulky,  makes  it  impossible 
to  use  them  to  advantage  in  the  manufacture  of  fertilizers 
without  previous  treatment.  The  use  of  these  materials, 
untreated,  can  only  be  regarded  as  desirable  when  they 
may  be  obtained  at  a  very  low  cost.  When  dissolved 
with  acid,  or  treated  in  such  a  way  as  to  render  them 
more  immediately  available,  they  may  be  used  to  ad- 
vantage, though  the  cost  of  such  treatment  is  usually 
so  great  as  to  make  it  impossible  to  thus  improve  their 
form  and  still  be  able  to  compete  commercially  with 
the  other  nitrogenous  products. 

VEGETABLE  NITROGENOUS  PRODUCTS 

Cotton-seed  meal  is  one  of  the  best  organic  nitrogenous 
fertilizing  materials  derived  from  vegetable  life.  When 
oil  is  extracted  from  cotton-seed,  the  residue  is  ground 
fine  and  sold  as  a  food  for  cattle  and  as  a  fertilizer.  Be- 
cause it  is  highly  valued  as  a  food  for  cattle,  it  has  been 
standardized  to  contain  38  to  42  per  cent  protein,  equiva- 
lent to  6  to  7  per  cent  nitrogen.  It  contains  besides  the 
nitrogen  often  as  much  as  3  per  cent  of  phosphoric  and 
2  per  cent  of  potash.  When  mixed  with  hulls  the  per- 
centages of  the  elements  of  plant-food  are  lower.  Tests 
made  show  that  it  ranks  with  blood  in  the  availability 
of  its  nitrogen.  Its  use  as  a  fertilizer  is  confined  largely 
to  the  southern  states,  where  cotton  is  a  staple  crop,  and 


44  Fertilizers 

it  may  be  secured  in  abundance  without  cost  of  trans- 
portations. Furthermore,  its  use  as  a  food  for  cattle  is 
becoming  more  thoroughly  understood  and  appreciated 
so  that  its  use  as  a  fertilizer  is  decreasing. 

Linseed  meal  is  a  material  somewhat  similar  in 
character  to  cotton-seed  meal.  It  contains  on  the 
average  5.5  per  cent  of  nitrogen.  The  demand  for 
this  product  for  feeding  purposes  at  good  prices  makes 
it,  however,  an  expensive  source  of  nitrogen. 

Castor  pomace,  the  waste  resulting  from  the  extraction 
of  oil  from  the  castor  bean,  is  also  a  valuable  nitrogenous 
fertilizer.  It  contains,  on  the  average,  6  per  cent  of  this 
element,  and  decays  rapidly  in  the  soil.  This  product 
differs  from  the  cotton-seed  and  linseed  meal,  in  that  it  is 
not  useful  as  a  cattle  food.  Practically  its  only  use  is 
as  a  fertilizer. 

Vegetable  pomaces.  —  There  are  a  number  of  pomace 
materials  of  local  interest,  including  apple  pomace,  tomato 
pomace,  pumpkin  pomace,  cranberry  pomace  and  the 
like,  which  are  used  to  a  considerable  extent  by  a  few 
individual  farmers.  These  materials  are  very  variable 
in  composition.  They  are  usually  used  without  drying 
and  the  content  of  moisture  is  almost  never  constant. 
Most  of, these  products  are  derived  from  fruits  or  vege- 
tables very  acid  in  character  and  the  acid  contained  is 
often  in  large  enough  quantities  to  be  injurious  unless 
composted  with  dirt  and  slaked  lime. 

NATURAL  GUANOS 

A  series  of  nitrogenous  products  which  constitute  still 
another  separate  class,  consists  of  the  various  natural 
guanos.  From  its  derivation  the  word  "  guano  "  means 


Nitrogenous  Fertilizers  45 

dung,  and  it  is  probably  one  of  the  oldest  materials  used 
as  a  fertilizer.  Its  use  dates  back  to  the  twelfth  century, 
but  it  was  not  until  the  middle  of  the  nineteenth  century 
that  its  value  became  generally  appreciated.  The  first 
shipments  were  made  from  Peru  to  European  ports  late 
in  the  year  of  1840.  The  use  of  these  products  spread 
rapidly  and  were  considered  a  valuable  source  of  nitrogen, 
though  at  the  present  time  they  are  not  commercially 
important,  owing  to  the  practical  exhaustion  of  the  best 
supplies.  Of  the  guanos,  the  product  obtained  from 
Peru,  or  from  the  islands  on  the  coast  of  that  country, 
is  the  richest  in  nitrogen.  It  is  derived  from  the  excre- 
ments and  bodies  of  sea-fowls. 

When  the  deposits  occur  in  regions  which  are  warm  and 
with  little  rainfall,  they  are  high  in  nitrogen,  especially  if 
considerable  time  has  elapsed  since  their  formation. 
Where  rainfall  is  more  plentiful,  even  occasional,  the 
nitrogen  is  readily  changed  by  microorganisms  to  soluble 
forms  which  are  leached  away  together  with  the  potash 
salts,  leaving  a  product  low  in  nitrogen  and  high  in  phos- 
phoric acid.  The  first  product  usually  contains  from  12 
to  14  per  cent  of  nitrogen  and  from  10  to  12  per  cent  of 
phosphoric  acid,  whereas  the  second  product  contains 
from  5  to  8  per  cent  of  nitrogen  and  from  20  to  25  per  cent 
of  phosphoric  acid.  It  must  be  remembered  that  guanos 
are  variable  and  each  successive  consignment  shows  a 
different  composition.  In  fact,  the  composition  of  these 
materials  is  of  a  very  complex  character.  The  nitrogen 
exists  largely  as  ammonia,  combined  with  oxalates, 
urates,  humates,  sulfates,  phosphates,  carbonates,  and  to 
some  extent  in  purely  organic  form.  In  these  forms  the 
nitrogen  is  quickly  available,  and  marvelous  results  are 
obtained  from  their  use. 


46  Fertilizers 

There  are  many  other  deposits  of  guano,  but  none  has 
been  found  which  are  so  valuable  as  the  Peruvian. 
Ichaboe  guano,  for  example,  is  at  present  exported, 
though  it  is  a  fresh  deposit,  and  is  annually  collected  for 
shipment.  Bat  guano  found  in  caves  in  Mexico  and  in 
some  of  the  southwestern  states  is  another  example. 
Both  are  inferior  to  Peruvian  guano.  They  contain 
less  nitrogen  and  a  very  considerable  amount  of  insoluble 
matter,  though  the  nitrogen  is  usually  in  a  good  form. 
In  the  case  of  the  latter,  a  considerable  portion  exists 
as  a  nitrate.  Owing  to  the  very  excellent  results  that  were 
obtained  from  the  early  use  of  guanos,  many  attempts 
have  been  made  to  improve  the  lower  grades  obtainable  at 
the  present  time,  by  the  addition  of  nitrogenous  matter 
of  a  higher  rate  of  availability.  These  rectified  or 
fortified  guanos,  while  containing  nitrogen  in  good  forms, 
cannot  entirely  substitute  the  original  guanos,  owing  to 
the  impossibility  of  adding  forms  identical  with  those 
existing  in  the  natural  product.  That  is,  the  total  con- 
tent of  nitrogen  in  a  rectified  guano  may  be  the  same  as 
in  the  genuine  product,  though  the  special  forms  and  their 
proportions  cannot  be  simulated.  The  distinctive  value 
of  the  natural  guanos  is  due  to  the  fact  that  the  nitrogen 
existed  in  a  number  of  different  soluble  compounds, 
which  became  available  at  different  times  in  the  soil, 
and  thus  constantly  fed  the  plant  with  this  element. 
The  fact  that  nitrogen  guanos  gave  such  good  results  is 
an  evidence  of  the  advantage  of  introducing  different 
forms  into  artificial  mixtures. 

It  is  argued  that  because  of  the  very  great  value  of 
guanos,  which  consist  very  largely  of  the  excrement 
of  fowls,  that  droppings  of  pigeons,  particularly,  and  of 
domestic  fowls  should  also  possess  a  high  value,  and  for 


Nitrogenous  Fertilizers  47 

this  reason  a  rather  fictitious  value  has  been  fixed  upon 
these  products.  These  products  differ  very  materially 
from  natural  guanos,  and  it  is  due  probably  both  to  the 
character  of  the  food  eaten  by  the  domestic  fowl,  and  to 
the  different  methods  by  which  the  material  is  obtained. 
The  birds  producing  the  guanos  feed  largely  upon  fish, 
a  highly  nitrogenous  food,  resulting  in  an  excrement 
richer  in  this  element  than  that  from  the  domestic  bird, 
feeding  largely  upon  vegetable  matter ;  and,  besides,  the 
former  were  accumulated  in  a  hot,  dry  climate,  which 
quickly  absorbs  the  moisture  contained  in  the  fresh 
droppings,  thus  leaving  it  in  a  much  drier  state  than  is 
the  case  with  the  domestic  product. 

MECHANICAL  CONDITION  SHOULD  BE  CONSIDERED 

It  will  be  observed  from  the  foregoing  brief  description 
of  the  chief  sources  of  organic  forms  of  nitrogen,  that  a 
very  wide  variation  occurs  both  in  the  composition  or 
content  of  nitrogen  in  these  products,  and  in  the  avail- 
ability of  their  nitrogen,  or  rapidity  with  which,  under 
similar  conditions,  it  is  given  up  to  plants.  The  fact 
that  a  substance  contains  nitrogen  in  considerable  amounts 
and  in  an  organic  form,  then,  is  not  a  sufficient  guide  as 
to  its  usefulness.  Its  mechanical  condition,  or  physical 
form,  must  also  be  taken  into  consideration,  and,  other 
things  being  equal,  the  tougher  and  denser  the  substances, 
the  longer  the  time  required  to  decay,  and  hence  the  more 
slowly  will  the  material  feed  the  plant. 

AMMONIA  COMPOUNDS.    See  Fig.  1,  Plate  1. 

As  already  stated,  nitrogen  does  not  feed  the  plants 
in  organic  forms;  it  must  first  decay.  The  first  prod- 


48  Fertilizers 

uct  of  the  decay  of  a  nitrogenous  organic  substance 
is  ammonia,  a  combination  of  two  elements,  hydrogen 
and  nitrogen.  As  the  organic  animal  or  vegetable  sub- 
stance which  contains  carbon,  hydrogen,  oxygen  and 
nitrogen  in  combination  breaks  up,  the  carbon  combines 
with  part  of  the  oxygen  to  form  carbonic  acid;  part  of 
the  hydrogen  also  combines  with  oxygen  to  form  water, 
and  the  nitrogen  combines  with  hydrogen  to  form  am- 
monia. Yet  even  in  this  form,  plants  do  not  absorb  it 
freely.  Ammonia  is  in  a  better  form  than  the  organic 
material,  because,  in  the  first  place,  it  is  soluble  in  most 
of  its  combinations  with  other  substances,  and  is  thus 
readily  distributed  in  the  soil,  and  in  the  second  place, 
it  is  very  liable  to  change.  That  is,  its  future  availability 
is  no  longer  dependent  upon  any  mechanical  or  physical 
form;  every  portion  or  pound  of  ammonia  is  as  good  as 
any  other  portion  or  pound.  Ammonia,  however,  does 
not  occur  as  a  natural  product,  like  the  organic  forms, 
blood,  meat  and  fish.  Commercial  forms  are  the  result 
of  a  manufacturing  process,  and  they  may  exist  as  dis- 
tinct chemical  substances;  as  sulfate  of  ammonia,  in 
which  case  the  ammonia  is  combined  with  sulfuric  acid; 
as  chlorid  of  ammonia,  in  which  case  it  is  combined  with 
hydrochloric  acid;  as  nitrate  of  ammonia,  in  which  case 
it  is  combined  with  nitric  acid ;  and  as  carbonate  of  am- 
monia, in  which  case  it  is  combined  with  carbonic  acid. 
Sulfate  of  ammonia  is  a  chemical  salt  which,  when  pure, 
contains  21.2  per  cent  of  nitrogen.  In  commercial 
forms,  however,  it  usually  contains  about  20  per  cent 
of  nitrogen.  It  is  obtained  from  the  dry  distillation  of 
animal  bone  in  the  manufacture  of  bone-black,  from  the 
distillation  of  coal  in  the  manufacture  of  illuminating 
gas,  and  from  coal  in  the  manufacture  of  coke.  The 


Nitrogenous  Fertilizers  49 

quantity  now  made  is  increasing  annually,  largely  be- 
cause of  the  improved  methods  used  in  the  manufacture 
of  coke,  which  permit  the  saving  of  the  ammonia. 
Its  chief  advantages  are  that  it  is  very  concentrated, 
therefore  reducing  the  cost  of  handling;  it  is  always  in 
the  same  form,  a  distinct  and  definite  product,  thus  render- 
ing its  purchase  a  safe  proceeding;  and  it  is  very  quick 
to  act,  thus  making  it  a  very  useful  form,  especially  for 
quick-growing  crops.  Its  physical  character  is  such  as  to 
permit  its  ready  distribution  in  a  mixture.  On  the  other 
hand,  it  should  not  be  mixed  with  an  alkaline  material, 
in  which  case  the  ammonia  is  liberated.  Such  substances 
are  wood-ashes,  basic-slag,  potassium  carbonate  and  slaked 
or  burned  lime. 

Calcium  cyanamid  is  not  an  ammonia  compound,  but 
it  is  thought  wise  to  consider  it  here  because  it  is  believed 
that  it  undergoes  a  gradual  change  when  brought  in 
contact  with  soil  moisture  and  forms  ammonia.  It  is  a 
comparatively  new  product  made  possible  by  the  develop- 
ments in  the  world  of  electricity.  This  material,  some- 
tunes  called  lime-nitrogen,  is  now  being  manufactured, 
by  two  plants  in  this  country.  In  its  manufacture 
finely  divided  calcium  carbide  is  placed  in  a  heated 
retort,  into  which  nitrogen,  obtained  by  liquefaction  of 
air  and  distillation,  is  passed.  The  resultant  material 
is  removed  in  the  form  of  a  hard  cake  which  is  finely 
ground,  and  after  thorough  aeration  is  ready  for  distribu- 
tion. When  calcium  cyanamid  is  free  of  impurities 
it  contains  35  per  cent  of  nitrogen,  but  the  commercial 
product  seldom  exceeds  15  per  cent.  While  its  avail- 
ability ranks  with  other  ammonium  salts  it  has  the 
disadvantage  of  causing  injury  to  young  plants  unless 
it  is  distributed  in  the  soil  some  time  before  planting. 


50  Fertilizers 

Differing  from  sulfate  of  ammonia  it  tends  to  sweeten 
soils  rather  than  cause  a  more  acid  condition. 

If  calcium  cyanamid  is  used  to  supply  a  part  of  the 
nitrogen  in  a  complete  fertilizer,  the  analysis  will  be 
somewhat  misleading.  In  the  chemical  analysis,  the 
form  in  which  the  nitrogen  derived  from  cyanamid  would 
be  reported  would  depend  upon  the  amounts  and  forms 
of  nitrogen  derived  from  other  sources  used  in  the  mix- 
ture. If  nitrate  of  soda  is  used  in  the  mixture,  the  amount 
of  nitrate  nitrogen  reported  will  be  greater  than  the  actual 
amount  derived  from  nitrate  of  soda,  a  portion  being 
obtained  from  the  cyanamid.  This  same  condition  is 
true  when  ammonia  salts  are  used,  a  part  of  the  nitrogen 
from  cyanamid  would  be  reported  as  ammonia  nitrogen. 
In  either  case  the  remaining  portion  of  nitrogen  from 
cyanamid  would  be  reported  as  water-soluble  organic 
nitrogen. 

NITRATE  NITROGEN 

Neither  organic  nor  ammonia  compounds  containing 
nitrogen  are  capable  of  fully  meeting  the  demands  of 
plants  for  this  element.  The  first,  or  organic  nitrogen, 
must  pass  through  two  changes,  first  to  ammonia,  and 
then  to  nitrate,  and  the  ammonia  must  change  to  a 
nitrate. 

This  process  already  referred  to  is  known  as  nitrifica- 
tion. The  nitrate  is  directly  absorbed  by  plants,  and  the 
larger  portion  obtained  by  them  is  taken  up  in  this  form. 
Hence,  from  the  standpoint  of  availability,  nitrate  nitrogen 
must  be  regarded  as  the  most  useful  form.  Like  ammonia 
too,  a  pound  of  it  is  as  good  as  any  other  pound,  from 
whatever  product  it  may  have  been  derived.  It  is  a 
relatively  concentrated  material;  and  as  it  is  perfectly 


Nitrogenous  Fertilizers  51 

soluble,  it  readily  distributes  itself  everywhere  in  the 
soil  to  which  it  may  be  applied. 

Nitrate  of  soda.  —  There  are  a  few  substances  found 
in  nature  containing  nitrogen  in  the  nitrate  form.  The 
most  important  is  nitrate  of  soda,  a  chemical  compound 
composed  of  sodium,  oxygen  and  nitrogen.  The  occur- 
rence of  this  material  is  limited  to  the  rainless  districts 
of  South  America,  mainly  Chile,  where  the  crude  nitrate 
of  soda  salts  called  Caliche  are  found  in  vast  quantities. 
These  crude  salts  contain  from  5  to  30  per  cent  of  nitrate 
of  soda.  In  the  process  of  refining  for  market  they  are 
dissolved  and  recrystallized  in  order  to  remove  as  far  as 
possible  the  impurities  associated  with  them.  There 
are  great  quantities  of  a  lower  grade  containing  3  per  cent 
or  less  of  nitrate  of  soda  which  are  not  at  present  con- 
sidered sufficiently  rich  to  refine.  The  chemically  pure 
salt,  nitrate  of  soda,  contains  16.47  per  cent  of  nitrogen, 
and  the  commercial  article,  called  "Chili  saltpeter," 
contains  from  15.5  to  16  per  cent.  The  impurities  which 
remain  in  it  consist  mainly  of  sodium  chlorid,  or  common 
salt,  which,  together  with  moisture,  causes  a  lower  per- 
centage in  the  commercial  product.  Because  nitrogen 
in  nitrate  of  soda  is  in  the  nitrate  form  and,  therefore, 
soluble,  it  is  often  advanced  that  there  is  greater  loss 
from  leaching  into  the  drainage  waters.  Experiments 
show  this  is  untrue  or  at  any  rate  the  efficiency  of  this 
material  is  greater  than  that  of  any  other  because  more 
is  returned  in  the  crop  as  shown  in  the  discussion  of  relative 
availability  of  the  forms  of  nitrogen  which  follows.  When 
nitrate  of  soda  is  mixed  with  other  materials  it  has  a 
tendency  to  cause  a  caking  or  hardening  of  the  mixture, 
but  this  is  no  more  true  of  nitrate  of  soda  than  of  the 
potash  salts.  Unlike  ammonium  sulfate,  nitrate  of  soda 


52  Fertilizers 

leaves  in  the  soil  an  alkaline  residue  rather  than  an  acid 
residue. 

The  search  for  deposits  of  crude  nitrate  salts  in  other 
parts  of  the  world  has  been  rather  fruitless,  but  it 
has  been  known  for  a  long  time  that  nitrate  exists  in 
Egypt  and  India  in  combination  with  potassium  rather 
than  sodium,  which  makes  these  deposits  even  more 
valuable  because  potassium  is  more  valuable  than  sodium 
in  these  countries.  Very  recently  nitrate  beds  have  been 
reported  in  some  parts  of  California,  but  the  reports  of  the 
composition  of  the  raw  material  have  been  unfavorable. 
If  the  most  convincing  theory  of  the  formation  of  the 
nitrate  beds  is  to  be  accepted,  —  namely,  that  gigantic 
islands  of  sea-grass  in  the  ocean  became  isolated  by 
volcanic  rising  of  the  ground,  and  subsequently  the  sea 
water  evaporating  they  remained  and  decayed,  —  it  is  not 
probable  that  new  beds  are  in  the  process  of  formation 
as  in  the  case  of  the  guanos  of  Peru.  But  there  is  little 
cause  for  alarm  because  experts  claim  the  Caliche  beds  of 
Chile  will  last  from  300  to  400  years  before  the  higher 
grade  salts  become  completely  exhausted  at  the  present 
rate  of  consumption. 

Calcium  nitrate  is  a  manufactured  product  of  compara- 
tively recent  origin  containing  its  nitrogen  in  the  nitrate 
form.  It  has  caused  much  confusion  because  many 
names  have  been  applied  to  the  same  material ;  as,  nitrate 
of  lime,  lime-saltpeter,  basic  calcium  nitrate,  lime-niter, 
basic  nitrate,  and  basic  lime-nitrate.  It  is  now  being 
manufactured  in  Norway,  Austria,  France  and  the 
United  States  from  atmospheric  nitrogen.  The  commer- 
cial product  is  a  mixture  of  lime  and  calcium  nitrate 
containing  12  to  14  per  cent  of  nitrogen,  though  it  often 
varies  as  much  as  from  9  to  14  per  cent  of  nitrogen. 


Nitrogenous  Fertilizers  53 

Potassium  nitrate.  —  It  has  already  been  stated  that 
potassium  nitrate  salts  exist  in  Egypt  and  India.  They 
are  also  found  in  Cape  Colony,  South  Africa.  The  impure 
salts  on  the  market,  commonly  called  niter  or  saltpeter, 
contain  14  per  cent  of  nitrogen  and  44  per  cent  of  potash. 
Because  this  material  is  used  for  manufacturing  purposes, 
especially  gunpowder,  little  is  sold  for  fertilizer  even 
though  it  is  especially  concentrated  considering  its  con- 
tent of  both  nitrogen  and  potash. 

Ammonium  nitrate  is  a  compound  now  being  manufac- 
tured in  Norway  which  is  superior  to  the  other  nitrogenous 
products  in  that  it  is  highly  concentrated  and  leaves  no 
injurious  residue  in  the  soil.  Chemically  pure,  it  contains 
35  per  cent  of  nitrogen,  one-half  in  the  ammonia  form 
and  one-half  in  the  nitrate  form.  The  commercial  prod- 
uct, yet  limited  in  quantity,  is  sold  on  the  dry  basis 
99.8  per  cent  pure.  At  the  present  time,  the  cost  of 
nitrogen  contained  is  too  high  to  warrant  the  use  of  this 
material  as  a  fertilizer. 


THE    RELATIVE    AVAILABILITY    OF   THE    DIFFERENT    FORMS 

OF  NITROGEN.    See  Fig.  2,  Plate  2. 

From  this  discussion  of  the  kind  and  source  of 
nitrogenous  fertilizer  supplies,  it  is  shown  that  the  form 
of  the  nitrogen  is  an  important  factor  in  determining  the 
rate  at  which  the  plants  may  obtain  it.  In  the  case  of 
nitrate,  the  form  is  such  as  to  enable  the  plants  to  take 
it  up  immediately.  It  is,  therefore,  theoretically  the 
best,  because  as  soon  as  it  comes  in  contact  with  the  roots, 
it  is  absorbed  by  them;  there  is  no  appreciable  time  re- 
quired to  enable  the  element  to  get  into  a  condition 
capable  of  ready  absorption  by  the  plant.  Furthermore, 


54  Fertilizers 

its  extreme  solubility  makes  it  possible,  when  moisture 
conditions  are  good,  to  reach  every  portion  of  the  soil  in 
which  the  roots  are  located,  so  that  it  is  not  only  more 
available  by  virtue  of  its  being  in  the  right  form,  but 
because  it  readily  goes  to  the  place  where  the  plant 
roots  are.  The  next  substance  in  order  of  availability 
is  ammonia,  and  the  rapidity  with  which  ammonia 
will  change  to  a  nitrate  makes  it  under  many 
circumstances  quite  as  useful.  It  possesses,  also,  one 
great  advantage  possessed  by  the  nitrate,  that  of  being 
soluble  in  water,  and  thus  readily  distributes  itself  through- 
out the  surface  soil.  The  difference  in  usefulness  of 
these  two  forms  seems  to  depend  more  largely  upon  the 
character  of  the  season  than  upon  the  exact  form.  In  a 
very  wet  season  the  nitrate  is  less  useful,  because  liable 
to  be  washed  below  the  reach  of  the  roots,  or  lost  alto- 
gether, and  in  a  dry  season  it  is  more  useful  than  the 
ammonia,  because  as  soon  as  it  is  in  solution  it  is  capable 
of  being  absorbed.  It  must  be  remembered,  however, 
that  these  two  forms  possess  the  further  advantage  over 
organic  forms,  that  they  are  definite  chemical  compounds, 
which  always  possess  the  same  characteristics,  and  under 
similar  conditions  they  always  act  in  the  same  way.  If 
nitrogen  is  purchased  as  ammonia,  the  source  of  the 
nitrogen  is  not  important ;  that  is,  whether  derived  from 
the  manufacture  of  illuminating  gas,  coke,  or  bone- 
black,  or  from  one  of  the  newer  ammonia  compounds,  if 
it  is  ammonia,  it  is  identical  in  character.  The  same  is 
true  of  nitrate  —  the  original  source  of  the  nitrogen  is 
immaterial. 

The  availability  of  nitrogen  in  organic  forms,  as  already 
pointed  out,  depends  upon  the  rapidity  with  which  they 
will  change  to  the  nitrate  under  varying  conditions. 


Nitrogenous  Fertilizers  55 

Such  products  as  dried  blood,  dried  meat,  dried  fish  and 
concentrated  tankage  change  rapidly,  and  are,  therefore, 
good  forms,  while  products  like  raw  leather  and  horn 
meal  are  very  slow  to  change. 

The  practical  point,  and  the  one  of  prime  importance 
to  the  farmer,  is,  then,  to  know  how  to  estimate  the  rela- 
tive value  or  usefulness  of  these  different  products,  what 
is  the  rate  of  availability  as  compared  with  nitrate,  and 
thus  the  relative  advantage  of  purchasing  the  one  or  the 
other,  at  the  ruling  market  prices.  Relative  values, 
however,  cannot  be  assigned  as  yet,  though  careful  studies 
of  the  problem  have  been  made,  chiefly  by  what  are  known 
as  "  vegetation  tests  " ;  that  is,  tests  which  show  the  actual 
amounts  of  nitrogen  that  plants  can  obtain  from  nitrog- 
enous products  of  different  kinds,  when  they  are  grown 
under  known  and  controlled  conditions.  An  enormous 
amount  of  work  has  been  devoted  to  the  comparison  of 
the  availabilities  of  the  nitrogen  of  the  different  substances 
under  different  conditions  and  with  different  crops,  and 
tables  have  been  prepared  showing  the  relations  thus  ob- 
served. The  comparative  availabilities  are  established  in 
these  tables  by  taking  the  yield  from  nitrate  nitrogen  at 
100,  and  using  this  as  a  standard  for  measuring  the  yields 
from  other  substances.  It  will  be  seen,  therefore,  that 
the  actual  availabilities  are  smaller  than  the  comparative 
availabilities,  since  the  return  from  nitrate  nitrogen  never 
actually  reaches  100  per  cent.  Furthermore,  while  practi- 
cally all  of  the  effect  from  the  application  of  nitrate  or 
ammonia  nitrogen  is  obtained  in  the  first  season,  the 
effect  from  manure  nitrogen  or  other  forms  of  organic 
nitrogen  is  often  considerable  in  the  second  and  even  the 
third  season  —  a  fact  which  must  not  be  overlooked  in 
the  study  of  availabilities.  The  following  tables  give 


56 


Fertilizers 


the  results  obtained  by  different  workers  under  average 
conditions.  It  also  shows  the  recovery  of  nitrogen  from 
different  forms.  The  values  given  are  far  from  fixed, 
since  changed  conditions  of  soil,  climate,  crop  and  the 
like  may  modify  them  to  a  considerable  extent.  At 
all  events,  they  are  a  fair  approximation  of  the  actual 
conditions  as  they  exist  in  most  soils. 

Comparative  availability  of  different  nitrogenous  substances. 


AUTHORITY 

WAG- 
NER 

AND 
DORSCH 

JOHN- 
SON 

VOORHEES 

WAG- 
NER 

AVER- 
AGE 

Nitrate  of  soda     .     . 

100 

100 

100 

100 

100 

Sulfate  of  ammonia  . 

90 

— 

— 

83 

86 

Cotton-seed  meal  .     . 

— 

76 

70 

— 

73 

Dried  blood      .     .     . 

70 

77 

70 

65 

70 

Horn  meal         .     .     . 

70 

72 

— 

65 

69 

Hoof  meal         .     .     . 

— 

72 

65 

— 

68 

Dried  fish          ... 

— 

70 

65 

— 

67 

Green  plant  substance 

70 

— 

— 

65 

67 

Tankage            .     .     . 

— 

68 

60 

— 

64 

Meat  meal        .     .     . 

60 

— 

65 

53 

59 

Bone-meal         .     .     . 

60 

— 

65 

53 

59 

Stable  manure      .     . 

45 

— 

— 

25 

35 

Variable  from 

Wool  waste       .     .     . 

30 

— 

2  to  30 

25 

27 

Variable  from 

Leather  meal    .    .    . 

20 

— 

2  to  30 

15 

17 

The  author's  figures  in  this  table  furnish  a  fair  basis  for 
comparing  the  different  materials,  when  used  for  the 
same  purpose  or  under  the  same  conditions.  If,  for 
example,  the  increased  yield  of  oats  due  to  the  applica- 
tion of  nitrate  of  soda  is  1000  pounds,  the  yield  from  blood 
and  cotton-seed  meal  would  be  700  pounds,  the  yield 


Nitrogenous  Fertilizers  57 

from  dried  ground  fish  and  hoof  meal  would  be  650  pounds, 
from  bone  and  tankage  600  pounds,  and  from  leather, 
ground  horn  and  wool  waste,  from  20  to  300  pounds. 
The  foregoing  discussion  shows  very  clearly  that 
organic,  ammonia  and  nitrate  nitrogen  have  a  very 
unequal  value  as  sources  of  nitrogen.  Nitrate  nitrogen, 
the  most  valuable  of  all  three,  is  seldom  if  ever  entirely 
used  by  the  crop.  Conditions  determine  in  a  large 
degree  the  proportion  of  the  nitrate  nitrogen  secured  by 
the  crop,  because  a  smaller  or  larger  amount  escapes 
beyond  the  reach  of  the  plant  by  leaching  or  into  the  air 
by  denitrification.  The  amount  of  nitrogen  returned  by 
the  crop  in  the  harvest  is,  therefore,  a  direct  means  of 
determining  the  relative  availability  of  nitrogen  from  the 
three  different  forms.  Investigations  conducted  by  Paul 
Wagner,  Darmstadt,  Germany,  and  the  author,  Edward. 
B.  Voorhees,  of  the  New  Jersey  Experiment  Station,  agree 
very  closely.  Conclusions  from  these  works  show  that 
there  was  returned  in  the  harvest  62  parts  of  nitrate 
nitrogen  for  every  hundred  parts  applied;  44  parts  of 
ammonia  nitrogen  for  every  hundred  parts  applied  and 
40  parts  of  organic  nitrogen  for  every  hundred  parts  ap- 
plied as  dried  blood.  Hence,  with  the  returns  from 
nitrate,  the  highest  recovery  regarded  as  100,  the  relative 
availability  of  the  nitrogen  as  ammonia  would  be  69.7 
and  of  nitrogen  as  dried  blood  as  64.4.  These  figures 
possess  great  practical  significance  to  the  farmer  buying 
and  using  the  nitrogen  now  offered  on  the  market  in 
fertilizers. 

Conditions  which  modify  availability. 

The  foregoing  discussion  and  figures  alone  are,  however, 
not  a  sufficient  guide  as  to  the  kinds  to  buy  under  all 


58  Fertilizers 

conditions,  since  the  usefulness  of  the  different  forms  are 
also  dependent  upon  such  other  conditions  as  the  char- 
acter of  soil,  kind  of  crop  season  and  the  object  of  the 
application. 

The  character  of  soil  is  an  important  factor.  The 
mechanical  composition  of  a  soil  is  a  dependable  guide  as 
to  the  rapidity  of  leaching  of  the  soluble  forms  of  nitrogen. 
A  loose  light  soil  permits  more  rapid  percolation  of  water 
through  it  to  the  lower  layers  below  the  reach  of  plant- 
roots  and  nitrogen  is  more  readily  leached  away  than  in 
heavier  soils  possessing  finer  particles.  Furthermore, 
some  soils  naturally  possess  conditions  favorable  to 
nitrification,  some  possess  similar  conditions  through  the 
efforts  of  man,  and  still  others  possess  conditions  unfavor- 
able to  nitrification.  Soils  sufficiently  open  and  porous 
to  permit  easy  cultivation  and  proper  circulation  of  air 
and  moisture,  and  well  supplied  with  lime  and  organic 
matter  possess  those  characteristics  favorable  to  the 
spread  and  development  of  bacteria  which  bring  about 
a  more  rapid  change  of  the  form  of  nitrogen.  Again, 
the  previous  treatment  of  a  soil  is  an  important  considera- 
tion. Liberal  applications  of  manure,  and  the  production 
and  use  of  leguminous  crops  for  manurial  purposes  tend 
to  build  up  the  content  of  organic  nitrogen  in  a  soil  so 
that  less  might  be  used  at  planting  time. 

The  kind  of  crop  is  an  important  factor,  since  certain 
crops  grow  and  develop  quickly,  while  others  grow  for 
a  comparatively  long  period.  Some  require  greater 
quantities  of  food  in  a  usable  form  and  others  feed  more 
slowly.  It  is  the  object  in  some  instances  to  produce 
succulence,  in  others  to  produce  grain.  The  season, 
likewise,  because  the  changes  from  organic  forms  to 
ammonia,  or  nitrate,  only  take  place  when  the  tempera- 


Nitrogenous  Fertilizers  59 

ture  reaches  37°  F.,  and  when  in  addition  sufficient  mois- 
ture is  present.  Hence,  a  material  which  might  give 
excellent  results  when  applied  to  a  crop  that  grows  through 
a  long  period  in  a  climate  where  the  season  is  very  warm 
and  moist,  might  be  very  unsatisfactory  where  the  season 
is  short,  cold  and  dry.  These  are  a  few  of  the  conditions 
which  modify  the  rate  of  the  decay  of  the  same  material. 
The  object  of  the  application  should  also  be  taken 
into  consideration.  The  rate  of  the  feeding  of  the  plant 
with  nitrogen  in  organic  forms  is  measured  by  the  rate 
of  decay  of  the  organic  material  containing  it,  while  when 
nitrate  is  used,  its  feeding  is  direct.  The  result  is  really 
a  sort  of  feeding  of  the  soil  in  the  one  case,  and  a  direct 
feeding  of  the  plants  in  the  other.  Where  the  purpose 
is  to  get  the  largest  proportionate  increase  in  crop  from 
the  least  amount  applied,  either  the  nitrate,  or  the  am- 
monia, or  the  more  active  of  the  organic  forms,  would  be 
likely  to  give  the  best  returns.  Whereas,  if  the  object 
to  be  attained  is  not  so  much  a  large  increased  crop  as  it 
is  increase  in  the  future  productive  capacity  of  the  soil 
in  respect  to  this  element,  the  slower  acting  materials 
will  often  answer  the  purpose  quite  as  well  as  the  use  of 
the  more  active  nitrate  form,  because  in  this  form  no 
insoluble  combinations  are  formed,  the  nitrate  is  freely 
movable,  and  if  the  plants  do  not  absorb  it,  and  heavy 
rains  come,  the  water  containing  the  nitrate  is  carried 
through  the  soil  into  the  drains  and  the  nitrogen  lost. 
The  disadvantage  of  the  nitrate  is,  then,  that  there  is 
a  greater  possibility  of  loss  from  its  use  than  from  the 
use  of  materials  which  are  either  insoluble,  or  which  are 
readily  absorbed.  Ammonia,  while  perfectly  soluble,  is 
fixed  by  the  other  substances  in  the  soil,  and  is  not,  there- 
fore, readily  leached  out.  If,  however,  heavy  applications 


60  Fertilizers 

are  made,  the  possibility  of  loss  is  increased,  because  of  the 
rapid  change  of  the  ammonia  into  the  nitrate  form.  In 
the  case  of  organic  materials,  the  losses  from  leaching 
are  seldom  worthy  of  consideration  in  good  practice, 
since  an  appreciable  time  is  required,  even  in  the  case 
of  the  best  forms,  to  change  all  of  the  nitrogen  into  am- 
monia, and  then  to  a  nitrate;  while  in  the  case  of  the 
poorer  forms,  still  more  time  is  necessary  to  cause  the 
change,  and  losses  are  not  liable  to  occur.  In  the  making 
up  of  fertilizers,  all  of  these  considerations  should  be  care- 
fully balanced.  It  is  the  practice  on  the  part  of  many 
manufacturers  to  use  a  part  of  each  of  the  three  forms, 
so  that  a  continuous  feeding  of  the  plant  may  be  insured. 
Therefore,  while  the  fact  remains  that  fertilizers  con- 
taining only  the  one  form  may  not  be  the  poorest,  the 
chances  are  that  those  which  contain  all  forms  are  likely 
to  give  more  satisfactory  results. 


CHAPTER  IV 

PHOSPHA  TES  —  THEIR     SOURCES,     COMPOSI- 
TION AND  RELATIVE  VALUE 

MANY  farmers  apply  the  term  "phosphate"  to  all 
manufactured  fertilizers,  without  regard  to  the  kind 
and  character  of  the  fertilizing  constituents  contained 
in  them.  The  term  "phosphate"  should  only  be  ap- 
plied to  materials  which  contain  phosphoric  acid,  and 
it  does  not  necessarily  imply  that  the  phosphoric  acid 
is  in  an  available  form.  The  term  "superphosphate" 
implies  that  the  phosphoric  acid  contained  in  the  material 
is  available.  The  phosphates  constitute  a  class  of  prod- 
ucts from  which  superphosphates  are  made,  and  which 
are  used  in  the  manufacture  of  fertilizers  that  contain 
immediately  useful  or  available  phosphoric  acid.  The 
following  discussion  of  phosphates  is  quoted  from  the 
author's  "First  Principles  of  Agriculture." 

The  phosphoric  acid  in  artificial  manures  is  derived 
from  compounds  called  "phosphates."  In  phosphates 
the  phosphoric  acid  is  united  with  lime,  iron  and  alumina, 
forming  phosphates  of  lime,  iron  and  alumina,  as  the 
case  may  be.  The  phosphates  of  lime  are  better  cal- 
culated for  the  purpose,  and  are,  therefore,  used  more 
largely  than  any  other  as  a  source  of  phosphoric  acid, 
in  the  manufacture  of  artificial  manures. 

The  phosphates  available  for  this  purpose  are  not, 
however,  pure  salts,  but  exist  in  combination  either 

61 


62  Fertilizers 

with  organic  substances,  or  with  minerals,  or  both,  the 
content  of  phosphoric  acid  and  its  combination  with 
other  substances  determining  the  usefulness  of  the  phos- 
phate to  the  manure-maker. 

The  phosphoric  acid  in  these  materials  is  soluble  with 
difficulty  in  the  soil  water;  and  hence  in  their  original 
condition,  or  in  the  crude  raw  forms,  they  give  up  this 
element  in  proportion  as  they  decompose  or  decay  in  the 
soil.  Those  in  combination  with  organic  substances, 
either  animal  or  vegetable,  are,  as  a  rule,  more  quickly 
useful  as  a  source  of  phosphoric  acid  than  those  composed 
entirely  of  mineral  constituents. 

PHOSPHATE  OF  LIME,  OR  BONE  PHOSPHATE  —  ANIMAL 

BONE 

The  bones  of  animals  are  the  chief  source  of  phos- 
phates that  exist  in  combination  with  organic  matter, 
and  were  for  a  long  time  the  main  source  for  manurial 
purposes. 

Bone  consists  chiefly  of  three  classes  of  substances; 
viz.,  moisture,  organic  matter,  containing  nitrogenous 
and  fatty  matter,  and  phosphate  of  lime,  or  bone  phos- 
phate —  the  proportion,  particularly  of  the  nitrogen 
and  phosphoric  acid,  depending  upon  the  kind  of  bone 
and  the  method  of  its  treatment. 

Bone  from  the  same  kind  of  animal  differs  in  com- 
position according  to  the  age  of  the  animal  and  its  loca- 
tion in  the  body.  In  a  general  way,  the  younger  the 
animal  the  softer  the  bone,  the  poorer  in  phosphate  of 
lime  and  the  richer  in  nitrogen;  the  older  the  animal, 
the  richer  in  phosphate  of  lime  and  the  poorer  in  nitrogen. 
The  large  and  hard  thigh  bones  of  an  ox,  for  instance, 


Phosphates  —  Their  Sources  '  63 

differ  in  composition  from  the  softer  and  more  porous 
bones  of  other  parts  of  the  body. 

The  phosphate  of  lime  of  the  harder  bones  is  dense 
and  compact;  that  from  the  softer  bone  is  more  open 
and  porous.  The  chief  cause  of  variation  in  the  com- 
position of  bones  used  as  manure,  however,  is  due  to 
the  treatment  they  receive.  This  is  recognized  by 
manufacturers  and  dealers,  and  different  names  of  brands 
are  used  to  indicate  the  method  of  manufacture  or  treat- 
ment. As  applied,  however,  they  do  not  always  corre- 
spond to  the  methods  of  treatment. 

Raw  bone. 

The  term  "raw  bone"  is  properly  applied  to  bone 
that  has  not  suffered  any  loss  of  its  original  constituents 
in  the  processes  of  its  manufacture,  and  is  for  this  reason 
highly  regarded  by  farmers,  who  believe  that  it  is  purer 
than  any  other  form.  This  is  true  in  a  large  measure, 
though  the  fact  that  it  is  raw  bone  is  not  altogether  an 
advantage  from  the  standpoint  of  usefulness.  Raw  bone 
too  often  contains  considerable  fatty  matter,  which 
makes  it  a  difficult  process  to  grind  it  fine,  and  which 
also  has  a  tendency  to  retard  the  decay  of  the  bone  in 
the  soil.  A  considerable  amount  of  fat  also  reduces 
proportionately  the  percentage  of  the  valuable  constitu- 
ents, phosphoric  acid  and  nitrogen.  Good  raw  bone, 
free  from  meat  and  excess  of  fat,  should  contain  on  the 
average  22  per  cent  of  phosphoric  acid  and  4  per  cent  of 
nitrogen. 

Fine  bone. 

The  trade  terms  "bone  meal,'*  "bone  dust"  and 
"fine  bone"  are  used  to  indicate  mechanical  condition, 


64  Fertilizers 

or  fineness  of  division,  and  do  not  refer  especially  to 
composition.  These  names  should  not  be  taken  as 
indicating  the  fineness  without  personal  examination, 
since  frequently  the  products  do  not,  in  this  respect, 
correspond  to  the  name. 

Boiled  and  steamed  bone. 

The  larger  portion  of  the  bone  used  as  manure  has 
been  boiled  or  steamed  for  the  purpose  of  freeing  it  from 
fat  and  nitrogenous  matter,  both  of  which  are  products 
valuable  for  other  purposes.  The  fat  is,  of  course,  of 
no  value  as  a  manure,  and  its  absence  is  an  advantage. 
The  nitrogen,  while  useful  as  a  manure,  is  extracted 
chiefly  for  the  purpose  of  making  glue  and  gelatine. 

By  boiling  or  steaming,  the  bone  suffers  a  loss  of  its 
original  constituents,  the  chief  result  of  which  is  to  change 
the  proportions  of  the  nitrogen  and  phosphoric  acid  con- 
tained in  it.  Steamed  or  boiled  bone  contains  more 
phosphoric  acid  and  less  nitrogen  than  raw  bone,  and 
is  also  more  variable  in  composition,  the  relative  per- 
centage of  these  constituents  depending  upon  the  degree 
of  steaming  or  boiling  to  which  the  bone  has  been  sub- 
jected. 

Bone  that  has  been  used  for  the  purpose  of  making 
glue,  where  the  chief  object  is  to  extract  the  nitrogenous 
matter,  contains  from  28  to  30  per  cent  of  phosphoric 
acid  and  from  1J  to  If  per  cent  of  nitrogen.  The  steam- 
ing of  bone,  particularly  when  conducted  at  high  pressure, 
also  exerts  a  favorable  effect  upon  the  physical  and 
mechanical  character  of  the  bone.  It  destroys  its  original 
structure,  makes  it  soft  and  crumbly,  and  often  reduces 
it  to  a  finer  state  of  division  than  can  be  readily  accom- 
plished by  grinding;  and,  since  it  is  also  free  from  fat, 


Phosphates  —  Their  Sources  65 

and  is  finer,  it  is  more  directly  useful  as  a  source  of  phos- 
phoric acid  to  plants  than  purer  raw  bone. 

In  some  cases,  the  fat  is  extracted  from  bone  by  means 
of  such  solvents  as  petroleum  or  benzine.  These  methods 
of  extracting  the  fat  have  the  advantage  of  increasing 
the  relative  proportion  of  the  nitrogen,  this  element 
not  being  attacked  by  the  solvents.  The  more  complete 
extraction  of  the  fat  and  moisture  by  these  methods  also 
aids  in  the  final  preparation  of  the  bone  by  grinding. 
Bone  prepared  in  this  way  frequently  contains  as  high 
as  6  per  cent  of  nitrogen  and  20  per  cent  of  phosphoric 
acid. 

The  nature  and  composition  of  animal  bone  is  such 
as  to  make  it  a  valuable  source  of  phosphoric  acid ;  and, 
while  it  is  largely  used  with  nitrogenous  and  potassic 
materials  in  the  manufacture  of  artificial  manures,  its 
best  use  is,  perhaps,  in  the  fine  ground  form,  particularly 
for  soil  improvement  and  for  slow-growing  crops. 

Phosphoric  acid  applied  in  this  form  gradually  gives 
up  nitrogen  and  phosphoric  acid  to  the  plant;  and  its 
physical  and  chemical  characteristics  are  such  that  it 
forms  in  the  soil,  during  the  growing  season,  no  com- 
pounds more  insoluble  than  the  bone  itself. 

Commercial  grades  of  bone. 

Because  bone  and  tankage  are  variable,  a  guarantee 
should  be  required.  The  market  has  recognized  this  as 
fair,  and  to-day  bone  is  sold  and  known  more  by  its  guaran- 
tee rather  than  by  its  source.  There  are  a  number  of 
grades  sold  under  guarantee  of  ammonia  and  bone  phos- 
phate of  lime  instead  of  nitrogen  and  phosphoric  acid. 
The  quantities  of  the  different  grades  are  becoming  less 
each  year,  and  there  is  often  some  variation  in  the  materials 
F 


66  Fertilizers 

offered  on  the  market.     Bone  of  the  following  analyses 
can  usually  be  secured  : 

GRADES  OP  BONE 


'ercentage                            Percentage 
immonia                 Bone  Phosphate  of  Lime 

Percentage 
Nitrogen 

Percentage 
Phosphoric  Acid 

H 

and 

60 

equivalent 

to 

1.23 

and 

27.5 

3 

and 

50 

equivalent 

to 

2.47 

and 

22.9 

4  to  4.5 

and 

45 

equivalent 

to 

3.29-3.70 

and 

19.6 

2 

and 

30 

equivalent 

to 

1.65 

and 

13.75 

Bone  tankage. 

Tankage  is  made  from  the  residue  remaining  after 
boiling  cattle  heads,  feet,  clippings,  cartilage  and  other 
refuse  animal  matter.  It  may  be  classed  with  boiled 
bone  in  reference  to  the  quality  of  its  phosphoric  acid. 
Its  agricultural  value  is  further  modified  by  the  fineness 
of  division;  it  is  frequently  substituted  for  bone  in  the 
manufacture  of  fertilizers,  where  phosphate  derived  from 
bone  is  regarded  as  an  important  constituent  of  the  mix- 
ture or  brand. 

While  the  market  shows  an  increased  tendency  to  limit 
such  products,  six  distinct  grades  still  exist  as  shown 
below : 

GRADES  OP  BONE  TANKAGE 

Percentage  Percentage 

Bone  Phosphate  of  Lime  Phosphoric  Acid 

18  to  19.0  equivalent  to  40 

16.0  equivalent  to  35 

13.5  equivalent  to  30 

11.5  equivalent  to  25 

9.0  equivalent  to  20 

7.0  equivalent  to  15 

It  will  be  observed  that  certain  grades  of  tankage  ap- 
proach the  composition  of  bone  in  their  content  of  phos- 


Phosphates  —  Their  Sources  67 

phoric  acid;  the  nitrogen  increases  as  the  phosphoric 
acid  decreases,  as  already  pointed  out  in  the  discussion 
of  nitrogenous  materials. 

Other  organic  products. 

There  are  also  other  products  which  should  not  be 
disregarded  in  a  discussion  of  phosphates,  though  because 
of  their  content  of  either  nitrogen  or  potash  they  are 
primarily  valued  for  them,  rather  than  for  the  phos- 
phoric acid.  A  good  example  is  the  dried  ground  fish, 
which  often  contains  as  high  as  8  per  cent  of  phosphoric 
acid,  or  an  equivalent  of  17  to  18  per  cent  of  bone  phos- 
phate of  lime.  The  phosphoric  acid  in  dried  fish  is  fre- 
quently more  available  than  in  other  organic  forms, 
owing  to  the  fact  that  in  the  drying  of  the  scrap  it  is 
often  necessary  to  add  sulfuric  acid  to  prevent  putre- 
faction. On  the  average,  more  than  one-half  of  the 
total  phosphoric  acid  in  this  product  is  in  an  available 
form. 

The  phosphoric  acid  contained  in  other  nitrogenous 
products,  as  cotton-seed  meal  and  castor  pomace,  while 
not  large,  is  of  some  importance,  as  it  is  relatively  more 
available  than  in  raw  bone  or  in  tankage. 

Bone-black,  or  animal  charcoal. 

This  material  becomes  an  important  source  of  phos- 
phoric acid  for  artificial  manures,  after  it  has  served  its 
chief  and  first  purpose  in  clarifying  sugar.  In  making 
bone-black,  only  the  best  bones  are  used ;  they  are  cleaned 
and  dried,  and  placed  in  air-tight  vessels,  and  heated 
until  all  volatile  matter  is  driven  off ;  the  resultant  prod- 
uct, which  retains  in  part  the  original  form  of  the  bone, 
is  then  ground  to  a  coarse  powder;  it  then  becomes  a 


68  Fertilizers 

bone  charcoal,  consisting  chiefly  of  carbon  and  phosphate 
of  lime,  though  also  containing  small  amounts  of  magnesia 
and  carbonate  of  lime. 

Bone-black,  as  received  from  the  refineries,  contains 
the  impurities  gathered  there,  consisting  chiefly  of  vege- 
table matter  and  moisture.  It  is  somewhat  variable  in 
composition,  containing  from  32  to  36  per  cent  of  phos- 
phoric acid  and  a  small  amount  of  nitrogen.  It  decays 
slowly  in  the  soil,  and  is  not  now  used  to  any  extent 
directly  as  a  manure. 

Bone-ash. 

Bone-ash  is  an  excellent,  though  not  large,  source 
of  phosphoric  acid.  It  is  exported  in  considerable  quan- 
tities from  South  America,  where  the  bones  are  burned 
and  the  bulk  reduced,  in  order  to  facilitate  transporta- 
tion. It  does  not  contain  nitrogen,  and  is  more  variable 
in  composition  than  bone-black,  though  usually  somewhat 
richer  in  phosphate  of  lime.  Good  samples  contain 
from  27  to  36  per  cent  of  phosphoric  acid. 

Bones  themselves,  and  the  phosphates  derived  from 
bones,  constitute  a  class  differing  from  other  phosphates 
used  in  making  manures,  in  that  they  are  derived  directly 
from  organic  materials  and,  as  a  class,  they  possess  char- 
acteristics, due  to  this  fact,  which  render  them  more 
useful  than  those  derived  from  purely  mineral  sources. 

MINERAL  PHOSPHATES 

These  constitute  a  class  of  products  differing  from  those 
of  immediate  or  recent  animal  origin  mainly  in  the  fact 
that  they  are  not  combined  with  organic  matter,  and  are 
more  dense  and  compact  in  their  structure.  They  occur 


Phosphates  —  Their  Sources  69 

in  several  different  forms,  and  are  procured  from  distinct 
sources. 

South  Carolina  rock  phosphates. 

These  are  found  both  on  the  land  and  in  the  beds  of 
rivers  in  the  vicinity  of  Charleston,  South  Carolina,  and 
are  sometimes  called  "Charleston  phosphates."  The  de- 
posits vary  in  thickness  from  one  to  twenty  feet,  through 
which  the  phosphate  is  distributed  in  the  form  of  lumps 
or  nodules,  ranging  in  weight  from  an  ounce  to  over  a  ton. 
These  nodules  are  irregular,  non-crystalline  masses,  often 
full  of  holes,  which  contain  clay  or  other  non-phosphatic 
materials.  That  obtained  from  the  river  is  called  "river 
phosphate,"  or  "river  rock";  and  that  from  the  land, 
"land  phosphate,"  or  "land  rock."  The  two  varieties 
do  not  differ  materially  in  composition,  particularly  in 
the  content  of  phosphoric  acid. 

The  rock  contains  from  26  to  28  per  cent  of  phosphoric 
acid.  Its  uniformity,  in  connection  with  the  fact  that  it 
contains  but  small  percentages  of  compounds  of  iron  and 
alumina,  minerals  which  prevent  its  best  use  by  the 
manufacturer,  make  it  a  highly  satisfactory  source  of 
phosphoric  acid. 

The  river  rock  is  secured  by  dredging;  that  from  the 
land  is  largely  dug.  In  either  case  it  is  washed  to  re- 
move the  adhering  matter,  and  then  dried,  when  it  is 
ready  for  grinding  or  shipment.  South  Carolina  rock 
phosphate,  when  very  finely  ground,  is  called  "floats." 
It  is  sometimes  used  upon  the  land  in  this  form,  and 
when  used  for  certain  crops,  as  turnips,  for  example,  and 
on  certain  soils,  notably  those  wet  and  heavy  and  rich  in 
vegetable  matter,  very  satisfactory  returns  are  obtained. 

These  deposits  were  first  worked  in  1868,  though  the 


70  Fertilizers 

presence  of  phosphate  at  this  point  was  known  at  a  much 
earlier  date. 

Florida  phosphates. 

The  presence  of  phosphate  in  commercial  quantities 
in  Florida  was  discovered  in  1888,  since  which  time 
very  great  progress  has  been  made  in  developing  the 
deposits.  The  deposits  occur  in  a  number  of  forms,  — 
first,  "soft  phosphate,"  a  whitish  product,  somewhat 
resembling  clay,  and  largely  contaminated  with  it; 
second,  "pebble  phosphate,"  consisting  of  hard  pebbles, 
occurring  both  in  river  beds  and  upon  the  land,  and 
mixed  with  other  materials;  and  third,  "rock,"  or  "bowl- 
der phosphate,"  which  occurs  in  the  form  of  stony  masses 
or  bowlders,  both  large  and  small.  These  three  forms 
also  differ  widely  in  composition,  both  in  reference  to 
their  content  of  phosphoric  acid  and  in  respect  to  the 
presence  of  other  minerals.  (See  Figs.  3-5,  Plates  III 
and  IV.) 

The  soft  phosphate  is  the  poorest  in  phosphoric  acid. 
It  is  easily  prepared,  and  is  largely  used  directly  upon 
the  land.  It  is  also  the  most  variable  in  composition, 
ranging  from  18  to  30  per  cent.  The  pebble  rock  is  also 
variable  in  composition,  though,  when  washed  free  of 
sand  and  clay,  it  is  richer  in  phosphoric  acid  than  the 
soft  variety.  Good  samples  contain  as  high  as  40  per 
cent  and  over  of  phosphoric  acid.  The  bulk  of  the 
"Florida  phosphate"  is  believed  to  exist  in  the  pebble 
form. 

The  rock  or  bowlder  phosphate,  though  apparently 
much  less  in  amount,  is  more  uniform  in  composition, 
and  is  much  richer  than  either  of  the  other  forms.  The 
clean,  dry  bowlder  phosphate  often  contains  as  high  as 


PLATE  III.  — Phosphate  Mining. 


FIG.  3.  —  PHOSPHATE  PIT,  DUNNE  LLON,  FLORIDA. 


FIG.  4.  —  MINING  PHOSPHATE  ROCK  BY  MEANS  OF  FLOATING  DREDGE. 


Phosphates  —  Their  Sources  71 

40  per  cent  phosphoric  acid,  far  exceeding  in  richness 
the  South  Carolina  rock  superphosphate. 

Canadian  apatite. 

This  material  is  a  crystallized  rock  of  true  mineral 
origin,  and  occurs  associated  to  a  greater  or  less  extent 
with  other  materials.  It  is,  therefore,  not  uniform  in 
character,  the  phosphoric  acid  varying  according  to 
the  amount  of  the  other  substances  present. 

It  is  mined  in  the  provinces  of  Quebec  and  Ontario, 
and  separated  into  various  grades  at  the  mines.  The 
mining  is  expensive,  and  the  necessity  for  grading  in 
addition  makes  the  cost  of  production  proportionately 
high.  The  highest  grade  of  this  phosphate  is  very  pure, 
containing  40  per  cent  of  phosphoric  acid. 

Tennessee  phosphate. 

The  phosphate  deposits  in  Tennessee  were  discov- 
ered in  November,  1894,  since  which  time  they  have 
been  exploited  and  a  rapid  development  made.  This 
phosphate  differs  from  the  phosphate  of  South  Carolina 
and  Florida  in  that  it  does  not  exist  as  nodules,  pebbles 
or  bowlders,  but  in  veins  and  pockets,  and,  therefore, 
does  not  need  to  be  washed  and  dried  previous  to  its 
treatment.  While  the  phosphates  from  the  various  de- 
posits are  not  uniform  in  their  composition,  it  is  possible 
to  secure  large  quantities  that  equal  or  exceed  30  to  32 
per  cent  of  phosphoric  acid,  or  70  per  cent  or  over  of 
bone  phosphate,  and  that  are  relatively  free  from  dele- 
terious substances,  thus  making  them  not  only  a  rich 
but  a  valuable  source  of  supply  for  the  manufacturers  of 
superphosphates. 


72  Fertilizers 

Recent  discoveries  in  western  states. 

The  development  of  the  phosphate  mines  of  South 
Carolina,  Florida  and  Tennessee  was  so  rapid  that  grave 
fears  were  entertained  of  complete  exhaustion.  The 
future  prosperity  of  the  agriculture  of  the  United  States, 
however,  has  been  assured  by  recent  discoveries  of  vast 
phosphate  fields  in  Idaho,  Wyoming  and  Montana. 
Estimates  of  the  size  of  these  deposits  are  much  greater 
than  those  of  the  eastern  United  States  already  developed 
and  the  material  is  of  a  distinctly  high-grade  character. 

The  conditions  surrounding  many  of  these  deposits 
are  especially  favorable  for  the  manufacture  of  acid 
phosphate.  Copper  smelters  are  situated  not  far  dis- 
tant which  are  capable  of  producing  enormous  quantities 
of  sulfuric  acid  as  a  by-product,  which,  as  brought  out 
later,  is  used  in  large  quantities  in  its  manufacture. 

Basic-slag. 

Thomas  phosphate  powder,  phosphate  slag,  odorless 
phosphate,  iron  phosphate  and  basic-slag  are  some  of 
the  names  given  to  a  waste  product  found  in  the  manu- 
facture of  steel  from  phosphatic  iron  ores  by  a  modification 
of  the  Bessemer  process  in  which  an  excess  of  calcium 
oxide  (lime)  is  used.  It  is  a  heavy,  black  powder  weighing 
more  than  any  of  the  more  common  fertilizer  materials, 
and  is  extremely  fine. 

The  use  of  basic-slag  is  confined  largely  to  the  coun- 
tries manufacturing  steel  from  ores  high  in  phosphorus. 
It  is  produced  in  large  quantities  in  England,  France 
and  Germany,  and  in  those  countries  is  riot  only  one  of 
the  cheapest  sources  of  phosphoric  acid,  but  is  regarded 
as  a  very  valuable  product.  The  composition  varies 


Phosphates  —  Their  Sources  73 

with  the  grade  of  ore  and  the  amount  of  lime  used  in  the 
process  of  manufacturing  steel.  The  imported  product 
usually  contains  15  to  19  per  cent  of  phosphoric  acid. 
Among  the  chief  constituents,  other  than  phosphorus, 
are  a  number  of  compounds  containing  calcium,  mag- 
nesium, iron,  manganese  and  silicon.  In  general  the 
composition  will  range  within  the  limits  following: 

Phosphoric  acid    .     .     .     .  12  to  20  per  cent 

Calcium  oxide       .     .     .     .  35  to  50  per  cent 

Magnesium  oxide ....  4  to    6  per  cent 

Manganese  oxido ....  5  to  10  per  cent 

Iron  oxide 12  to  18  per  cent 

Silica 4  to    8  per  cent 

Alumina 1  to    3  per  cent 

The  availability  of  basic-slag  is  dependent  in  large 
measure  upon  the  fineness  of  division  and  soil  conditions. 
From  80  to  90  per  cent  of  the  total  phosphoric  acid  con- 
tained in  it  is  guaranteed  available,  but  experimental 
evidence  shows  that  the  phosphoric  acid  in  basic  slag  is 
only  a  little  more  than  one-half  as  quickly  available  as 
soluble  calcium  phosphate.  The  lime  contained  is  un- 
doubtedly an  asset.  Good  results  have  been  obtained 
on  low  wet  soils,  but  it  is  only  when  the  material  is  used 
in  large  quantity  that  the  effects  of  the  lime  become 
noticeable. 

Manufactured  phosphates. 

There  are  a  number  of  phosphatic  materials  manu- 
factured in  one  way  or  another  from  minerals  bearing 
phosphorus  which  are  mentioned  more  as  a  matter  of 
interest  than  of  practical  importance. 

Artificial  basic-slag  weal.  —  Many  attempts  have  been 
made  to  produce  by  manufacture  a  material  similar  to 


74  Fertilizers 

basic-slag.  When  apatite  or  other  phosphates  are  fused 
with  lime  and  silica,  a  product  is  formed  which  is  very 
similar  to  basic-slag,  known  as  artificial  basic-slag  meal. 

Wiborgh  phosphate.  —  By  fusing  feldspar,  sodium  car- 
bonate and  phosphorite  at  a  very  high  temperature,  a 
product  is  obtained  which  contains  from  20  to  30  per 
cent  of  available  phosphoric  acid.  It  has  been  found  to 
compare  very  favorably  with  superphosphates  and  basic- 
slag,  especially  when  used  upon  muck  and  peat  soils. 
The  cost  of  manufacture  is  too  great  to  make  this  material 
of  practical  importance. 

Walter  phosphate.  —  This  material  is  manufactured  by 
fusing  powdered  phosphorite,  sodium  sulfate,  calcium 
carbonate,  sand  and  coke.  When  the  material  is  hot 
it  is  run  into  water  and  finely  pulverized  after  cooling. 
It  compares  favorably  with  basic-slag. 

Palmaer  phosphate.  —  This  is  a  high-grade  phosphatic 
material  containing  35  to  40  per  cent  of  phosphoric  acid 
in  the  reverted  form,  practically  all  of  which  is  available. 
It  is  of  especial  importance  because  it  affords  a  means 
of  utilizing  mineral  apatite.  In  the  process  of  manu- 
facture apatite  is  treated  with  chloric  or  perchloric  acid 
generated  by  electricity  from  sodium  salts.  It  is  more 
effective  than  basic-slag  and  compares  favorably  with 
superphosphates. 

Phosphatic  guanos. 

Guanos  rich  in  phosphoric  acid  were  for  many  years 
previous  to  the  development  of  the  phosphate  mines 
used  extensively  in  this  country.  The  Peruvian  guano 
of  earlier  times  was  particularly  rich  in  nitrogen;  the 
purely  phosphatic  guanos  are  rich  in  phosphoric  acid, 
and  are  excellent  materials.  Very  little  of  this  material 


Phosphates  —  Their  Sources  75 

reaches  our  markets  to-day,  but  an  occasional  shipment 
is  brought  in  from  the  West  Indies  or  islands  of  the  Pacific 
Ocean. 


PHOSPHATES  AS  SOURCES  OF  PHOSPHORIC  ACID  TO 
PLANTS 

The  phosphates  mentioned  constitute  what  are  called 
"  raw  materials,"  and,  with  the  exception  of  bone,  are 
not  largely  used  directly,  or  without  further  treatment 
to  render  the  phosphoric  acid  more  soluble,  and  thus 
more  immediately  available  to  plants.  As  already  stated, 
the  phosphoric  acid  in  them  becomes  food  in  proportion 
to  the  rapidity  of  decay,  which  is  influenced  both  by  the 
character  of  the  material  and  the  fineness  of  its  division. 
Fine  materials,  too,  permit  of  a  more  even  distribution, 
thus  bringing  more  particles  of  phosphate  in  contact 
with  the  roots  of  plants. 

As  already  stated,  a  phosphate  is  a  substance  in  which 
the  phosphoric  acid  is  combined  with  lime,  iron  or  alumina. 
The  phosphates  of  lime  are  the  only  ones  that  are  used 
to  any  extent  in  the  manufacture  of  artificial  fertilizers. 
The  phosphoric  acid  contained  in  animal  bone  is  in  the 
form  of  phosphate  of  lime,  hence  the  term  "bone  phos- 
phate of  lime"  has  been  applied  to  all  phosphates  that 
contain  their  phosphoric  acid  as  phosphate  of  lime.  In 
fact,  statements  of  analysis  of  iron  and  alumina  phos- 
phates are  frequently  expressed  in  terms  of  phosphate 
of  lime.  That  is,  the  content  of  phosphoric  acid  is  stated 
as  equivalent  to  a  certain  percentage  of  bone  phosphate, 
the  term  expressing  the  total  amount  of  combined  phos- 
phoric acid;  as,  for  example,  a  bone  which  contains  20 
per  cent  of  phosphoric  acid,  which  is  the  average  content 


76  Fertilizers 

in  good  bone,  is  equivalent  to  43.60  per  cent  of  phosphate 
of  lime. 

All  phosphates  are  insoluble  in  water,  but,  as  phos- 
phates, they  are  not  capable  of  feeding  the  plant  directly ; 
they  must  first  decay.  Hence,  the  usefulness  of  a  phos- 
phate depends  upon  the  rate  of  decay,  or  time  required 
to  change  to  such  a  form  as  to  become  available  to  the 
plant.  The  rapidity  with  which  a  phosphate  will  feed 
the  plant  depends  upon  a  number  of  conditions,  chief 
among  which  are,  first,  the  character  of  the  substance 
itself;  second,  the  fineness  of  its  division;  third,  the 
character  of  the  soil  to  which  it  is  applied ;  and  fourth, 
the  kind  of  crop  for  which  it  is  used. 

The  influence  of  source  of  phosphate  upon  availability. 

The  chief  point  to  be  observed  in  the  first  case  is 
whether  the  substance  is  animal  or  vegetable,  or  whether 
it  is  mineral.  Phosphates  of  immediate  animal  or  vege- 
table origin  decay  more  rapidly  than  purely  mineral 
phosphates,  because  of  the  greater  tendency  of  the  organic 
matter  with  which  the  phosphate  is  associated  to  respond 
to  the  action  of  the  natural  agencies  which  cause  decay. 
A  bone,  for  example,  if  kept  in  a  suitable  condition  of 
moisture  and  warmth,  will  soon  begin  to  rot,  the  rotting 
affecting  not  only  the  animal  matter,  but  more  or  less  the 
phosphatic  matter  with  which  it  is  so  closely  identified, 
the  fermentation  primarily  attacking  the  organic  sub- 
stances, but  exercising  a  greater  or  less  solvent  effect 
upon  the  phosphates. 

In  the  case  of  the  mineral  substances,  the  rate  of  decay 
is  usually  much  slower,  because  there  is  no  organic  fer- 
mentation. The  material  changes  or  is  broken  up  only 
by  virtue  of  the  action  of  the  natural  solvents,  air  and 


Phosphates  —  Their  Sources  77 

water,  and  solvent  substances  in  the  soil.  Furthermore, 
the  phosphate  of  the  animal  bone  is  always  a  phosphate 
of  lime,  which,  while  not  soluble,  is  in  itself  more  readily 
attacked  by  the  natural  agencies  than  a  mineral  phos- 
phate which  has  associated  with  the  bone  phosphate 
other  minerals  that  are  not  readily  attacked  by  those 
agencies.  That  is,  the  mineral  phosphates,  while  they 
are  made  up  chiefly  of  phosphate  of  lime,  are  associated 
with  other  minerals,  as  iron  and  alumina,  that  are  more 
slowly  attacked  than  the  phosphate  of  lime  itself,  and  to 
some  extent,  too,  prevent  the  full  effect  of  the  solvents, 
rather  than  encourage  their  action,  as  is  the  case  with 
bone. 

Influence  of  fineness  of  division. 

In  the  second  place,  fineness  of  division  has  an  im- 
portant bearing  upon  availability,  since  the  finer  the 
substance  is  ground,  the  greater  will  be  the  surface  area 
exposed  to  the  natural  agencies  which  cause  decay. 
Thus  the  application  of  a  coarsely  ground  phosphate 
may  not  show  any  results  the  first  season,  while  the  same 
substance  ground  to  a  powder  may  have  a  good  effect 
the  first  season ;  that  is,  its  fineness  permits  of  the  solu- 
bility of  a  considerable  portion  of  its  phosphoric  acid. 

The  character  of  soil  as  a  factor  influencing  availability. 

In  the  third  place,  the  kind  of  soil  to  which  the  phos- 
phate is  applied  may  influence  the  rate  at  which  the 
plants  may  obtain  it.  A  soil  which  is  open  and  porous, 
and  thus  permits  the  free  access  of  air  and  circulation  of 
water,  and  one  which  contains  a  large  portion  of  other 
matter  capable  of  decay,  vegetable  or  animal,  presents 
more  favorable  conditions  for  the  solubility  of  phosphates 


78  Fertilizers 

than  one  which  is  close  and  compact  in  texture  and  purely 
mineral  in  its  character,  thus  preventing  the  free  access 
of  air  and  water,  and  in  which  no  organic  changes  are 
taking  place.  In  the  one  case  the  conditions  are  such 
as  to  favor  the  action  of  the  natural  agencies,  and  in  the 
other  they  are  such  as  to  retard  their  action. 

Influence  of  the  kind  of  crop. 

In  the  fourth  place,  the  value  or  usefulness  of  phos- 
phates is  measured  to  some  extent  by  the  characteristics 
of  the  plant  or  crop  to  which  they  are  applied.  Plants 
differ  in  their  power  of  acquiring  food.  Certain  plants 
are  able,  because  of  their  peculiar  root  system,  or  period 
of  growth,  to  appropriate  food  more  readily  from  in- 
soluble sources  than  others. 

General  considerations. 

All  these  considerations  must  be  observed  in  determin- 
ing the  usefulness  of  a  phosphate.  It  is  believed  by 
experienced  farmers,  though  not  absolutely  confirmed 
by  experimental  inquiry,  that  animal  bone,  for  example, 
is  far  superior,  as  a  source  of  phosphoric  acid,  for  most 
crops,  to  the  mineral  phosphates,  though  both  may  be 
ground  to  the  same  degree  of  fineness ;  and  also,  that  the 
finer  the  bone  is  ground,  the  more  rapidly  will  it  give  up 
its  phosphoric  acid. 

Laboratory  tests  show  that  the  phosphoric  acid  in 
bone,  while  insoluble  in  water,  may  be  partly  dissolved 
at  a  certain  temperature  by  a  neutral  solution  of  am- 
monium citrate.  This  medium  is  used  to  determine 
what  is  called  "available"  in  other  phosphatic  products. 
The  rate  of  solubility  in  this  medium  is  measured  by 
the  method  of  preparation  of  the  bone  and  its  fineness, 


Phosphates  —  Their  Sources  79 

the  phosphate  in  raw  bone  meal  of  the  same  fineness 
showing  rather  a  lower  rate  of  solubility  than  the  phos- 
phates in  steamed  bone.  The  phosphate  in  the  finest 
steamed  bone  is  much  more  soluble  than  that  in  the 
coarser  grades.  This  measure  of  the  rate  of  solubility 
of  bone,  while  not,  perhaps,  showing  the  exact  rate  at 
which  the  plants  may  obtain  it,  is  a  fairly  safe  guide  in 
its  use  for  most  crops,  as  compared  with  those  mineral 
phosphates  which  are  not  perceptibly  soluble  in  this 
medium.  The  range  of  solubility  of  different  kinds  and 
grades  of  bone  is  from  20  to  75  per  cent,  and  the  average 
of  a  large  number  show  about  30  per  cent  soluble  in 
citrate  of  ammonia,  which  would  be  called  "available" 
if  found  in  mixed  fertilizers,  and  probably  can  be  as  safely 
depended  upon  as  the  available  shown  in  other  products. 

In  any  case,  animal  bone,  or  finely  ground  mineral 
phosphates,  cannot  be  depended  upon  to  meet  fully  the 
needs  of  quick-growing  crops  for  phosphoric  acid,  but 
may  answer  an  excellent  purpose  where  the  object  is 
to  improve  gradually  the  soil  in  its  content  of  this  con- 
stituent, as  well  as  to  supply  such  crops  as  are  continuous, 
or  that  grow  through  long  periods,  as,  for  example, 
meadows,  pastures  and  orchard  and  vineyard  crops. 

As  to  the  specific  substance,  the  iron  phosphate,  or 
Thomas  phosphate  powder,  experiments  in  Europe  have 
shown  that  it  possesses  a  higher  rate  of  availability  than 
other  phosphates  which  are  insoluble  in  water,  but  which 
show  the  same  rate  of  solubility  in  ammonium  citrate, 
though  its  solubility,  or  availability,  is  measured  to  some 
extent  by  the  degree  of  fineness  to  which  it  is  ground; 
and  it  is  believed  that  its  special  form,  the  tetra-calcic, 
also  exercises  a  considerable  influence  upon  the  rate  of 
availability. 


80  Fertilizers 

European  vegetation  and  field  experiments  show  pretty 
clearly  that  two  parts  of  phosphoric  acid  from  the  Thomas 
phosphate  powder  are  approximately  equivalent  to  one 
part  from  soluble  phosphoric  acid,  and  that  this  phosphate 
is  especially  useful  on  wet,  marshy  soils  and  those  poor  in 
lime.  Experiments  conducted  in  this  country  practically 
confirm  these  conclusions. 

The  relative  availability  of  the  phosphates  in  the 
natural  guanos  has  also  been  shown  to  be  somewhat 
higher  than  in  other  insoluble  phosphates.  These  latter 
substances  for  this  reason  possess  a  distinct  value  over 
others  for  certain  classes  of  crops,  as,  for  example,  cran- 
berries, where  the  soluble  phosphates  would  be  liable  to 
be  washed  out,  and  where  the  organic  phosphates  would 
be  liable  to  float  on  the  surface  of  the  water,  and  also 
where  lands  are  cold  and  sour,  and  not  readily  fermentable. 

The  practical  point,  however,  to  the  farmer  is  the 
amount  of  increase  that  he  may  obtain  from  a  certain 
definite  expenditure,  a  matter  which  will  be  discussed 
later,  in  the  discussion  of  the  use  of  fertilizers  for  the 
various  crops. 


CHAPTER  V 
SUPERPHOSPHA  TES  —  POTASH 

THE  different  phosphates  mentioned  in  the  previous 
chapter  constitute  the  sources  of  supply  for  the  manufac- 
ture of  commercial  fertilizers.  That  is,  with  the  exception 
of  animal  bone,  Thomas  phosphate  powder  and  natural 
guanos,  they  are  used  more  extensively  for  this  purpose 
than  directly  on  the  land  in  their  raw  state.  They  are  the 
raw  materials  from  which  the  manufactured  phosphatic 
fertilizers  are  derived.  The  purpose  of  the  manufacture 
is  to  convert  them  into  a  form  in  which  the  phosphoric 
acid  is  immediately  available,  and  thus  directly  useful 
to  the  plant.  The  term  "available"  in  this  case  is  used 
in  the  same  sense  as  in  the  discussion  of  the  forms 
of  nitrogen  (Chapter  III),  and  it  means  that  when 
the  phosphoric  acid  is  in  this  form,  the  plants  may 
acquire  it  immediately. 

INSOLUBLE  PHOSPHORIC  ACID 

Phosphate  of  lime  is,  chemically  speaking,  a  salt  capable 
of  existing  in  various  forms,  the  form  measuring  in  large 
degree  the  rate  of  availability.  The  phosphate  of  lime, 
as  it  exists  in  the  animal  bone  and  mineral  phosphates, 
for  example,  consists  of  three  parts  of  lime  and  one  of 
phosphoric  acid.  This  is  the  insoluble  form.  It  is  not 
immediately  available,  and  because  of  the  three  parts  of 
G  81 


82  Fertilizers 

lime  to  one  of  phosphoric  acid,  which  it  contains,  it  is  also 
called  tricalcic,  tribasic  or  bone  phosphate,  and  is  graph- 
ically expressed  in  this  formula : 

Lime 

Lime          Phosphoric  Aoid 

Lime 

That  is,  in  each  molecule,  however  small,  there  are  three 
parts  of  lime  and  one  part  of  phosphoric  acid. 

SOLUBLE  PHOSPHORIC  ACID 

In  another  form,  the  phosphate  consists  of  one  part  of 
lime  and  one  of  phosphoric  acid,  two  parts  of  the  lime  in 
the  tricalcic  form  being  replaced  with  water.  This  form 
is  called  monobasic,  or  monocalcic.  It  is  a  saturated 
phosphate.  There  could  be  no  less  than  one  part  of  lime 
to  one  of  phosphoric  acid,  and  such  phosphates  are  called 
acid  phosphates,  or  superphosphates.  The  combination 
of  the  lime  and  phosphoric  acid  may  be  shown  as  follows : 

Lime 

Water          Phosphoric  Aoid 

Water 

This  form  is  completely  soluble  in  water  and  immedi- 
ately available,  and  when  applied  to  the  soil  readily  distrib- 
utes itself  everywhere,  thus  making  it  more  useful  than 
any  other  form. 

REVERTED  PHOSPHORIC  ACID 

Another  form  of  phosphate  consists  of  two  parts  of  lime 
and  one  part  of  phosphoric  acid,  and  is  called  dicalcic, 


Superphosphates  —  Potash  83 

dibasic  or  reverted.  One  part  of  the  lime  in  the  insoluble 
is  replaced  by  an  equivalent  of  water,  and  is  expressed  as 
follows : 

Lime 

Lime          Phosphoric  Acid 

Water 

The  reverted  form,  which  means  a  going  back  from  the 
soluble  toward  the  insoluble  form,  is  also  insoluble  in 
water,  but  is  readily  soluble  to  the  roots  of  plants. 

It  was  formerly  supposed  that  these  three  were  the  only 
forms  in  which  phosphoric  acid  existed,  but  another  form, 
in  which  four  parts  of  lime  are  combined  with  one  of  phos- 
phoric acid,  and  thus  called  tetrabasic,  or  tetracalcic,  has 
been  found  quite  recently  to  exist  in  the  Thomas  phosphate 
powder : 

Lime 

Lime          Phosphoric  Acid 
Lime 

This  form  is  insoluble  in  water,  though  it  has  been  found 
to  be  more  available  than  the  insoluble  tribasic  form. 

HOW  SUPERPHOSPHATES  ARE  MADE 

Any  material  which  contains  a  high  content  of  the  tri- 
calcic  or  bone  phosphate,  60  per  cent  or  over,  is  suitable 
for  the  manufacture  of  superphosphates,  provided  it  does 
not  possess  a  too  high  content  of  deleterious  substances. 
In  the  manufacture  of  superphosphates,  the  phosphate  is 
first  ground  to  a  fine  powder,  then  mixed  with  sulfuric  acid. 
The  acid  dissolves  the  phosphate,  and  two  parts  of  the 
lime  which  are  combined  with  the  phosphoric  acid  in  the 
tricalcic  form  are  first  set  free,  and  then  combined  with  the 


84  Fertilizers 

sulfuric  acid,  making  a  superphosphate  (monocalcic),  and 
a  sulfate  of  lime  or  gypsum.  That  is,  in  this  process,  two 
of  the  three  parts  of  the  lime  combined  with  the  phosphoric 
acid  to  form  the  insoluble  phosphoric  acid,  are  removed, 
thus  leaving  one  part  of  the  lime  combined  with  the  phos- 
phoric acid,  making  the  superphosphate.  A  pure  super- 
phosphate is,  therefore,  a  mixture  of  soluble  phosphate 
and  of  sulfate  of  lime  or  gypsum. 

The  difference  in  the  superphosphates  made  from  the  different 
materials. 

In  the  early  use  of  superphosphates,  the  chief  raw  mate- 
rial was  animal  bone.  The  superiority  of  the  bone  super- 
phosphate, or  dissolved  bone,  as  it  was  called,  over  the  raw 
bone  was  manifest  at  once,  and  the  familiarity  with  genu- 
ine bone  superphosphates  thus  early  acquired  by  farmers 
was,  perhaps,  quite  as  influential  as  any  other  in  creating 
a  prejudice  in  favor  of  their  continued  use  in  preference  to 
superphosphates  derived  from  mineral  phosphates.  The 
opinion  that  the  bone  superphosphate  is  "the  best" 
is  held  even  at  the  present  day,  notwithstanding  the  equally 
satisfactory  results  that  have  been  obtained  from  the  use 
of  the  superphosphates  from  other  sources. 

Soluble  phosphoric  acid  chemically  identical,  from  whatever 
source  derived. 

Chemically  speaking,  the  soluble  phosphoric  acid  pro- 
duced by  the  action  of  sulfuric  acid  upon  mineral  phosphates 
is  identical  with  the  soluble  phosphoric  acid  derived  from 
animal  bone,  and  if  the  soluble  from  each  could  be  separated 
from  the  other  substances  with  which  they  are  associated, 
there  would  be  no  difference  whatever  in  the  results  of 
their  use.  They  are  identical;  just  as  much  so  as  am- 


Superphosphates  —  Potash  85 

monia  obtained  in  the  manufacture  of  bone-black  from 
bones  is  identical  with  the  ammonia  obtained  in  the  manu- 
facture of  illuminating  gas  or  coke.  In  many  cases, 
doubtless,  superior  results  have  been  obtained  from  the 
use  of  the  animal  bone  superphosphate,  though  this  has 
not  been  due  to  any  inferiority  of  the  available  phosphoric 
acid  in  the  mineral  superphosphate,  but  rather  to  the 
fact  that  substances  have  been  compared  that  are  not 
strictly  comparable.  They  are  radically  different.  The 
one  contains,  in  addition  to  its  available  phosphoric  acid, 
the  only  fertilizing  ingredient  in  the  mineral  superphos- 
phate, considerable  nitrogen,  and,  moreover,  it  contains  its 
insoluble  phosphoric  acid  in  a  form  that  is  liable  to  decay 
more  rapidly  than  the  insoluble  in  the  mineral  phosphate. 
Soluble  phosphoric  acid  is  a  definite  compound.  The 
source  from  which  it  is  derived  does  not  influence  this 
point,  and  the  action  of  a  definite  quantity  is  also  identical 
when  conditions  are  similar. 


PHOSPHATES  AND  SUPERPHOSPHATES  ARE  NOT  IDENTICAL 

The  idea  in  the  term  "phosphate"  should  also  be  kept 
distinct  from  that  conveyed  by  the  term  "superphos- 
phate." The  first  means,  and  should  be  applied  to,  any 
material  containing  as  its  chief  constituent  phosphoric 
acid ;  the  other  means,  and  should  be  applied  to,  any 
material  containing  soluble  phosphoric  acid  as  its  chief 
constitutent.  The  phosphates  which  have  already  been 
described  are  each  capable  of  being  converted  into  a 
superphosphate,  as  animal  bone  superphosphate,  South 
Carolina  rock  superphosphate,  bone-black  superphosphate, 
bone-ash  superphosphate,  Florida  rock  superphosphate, 
and  Tennessee  rock  superphosphate.  These  superphos- 


86  Fertilizers 

phates  vary  in  their  content  of  soluble  phosphoric  acid, 
due  both  to  the  variation  in  the  content  of  the  phosphoric 
acid  in  the  phosphates  used  as  raw  materials,  and  to  the 
excellence  of  the  method  of  manufacture.  In  other  words, 
the  superphosphates,  while  practically  identical  in  so  far 
as  the  form  of  phosphoric  acid  is  concerned,  vary  in  their 
total  content  of  soluble  phosphoric  acid.  For  example, 
superphosphates  made  from  the  animal  phosphates,  as 
bone-black,  bone-ash  and  the  like,  are  usually  richer  in 
soluble  phosphoric  acid  than  those  made  from  animal  bone, 
or  from  many  of  the  mineral  phosphates,  because  these 
phosphates  are  of  such  a  character  as  to  enable  the  manu- 
facturer to  convert  all  the  phosphoric  acid  present  into  a 
soluble  form,  and  at  the  same  time  to  secure  a  fine,  dry 
product,  that  may  be  readily  handled  —  an  important 
consideration  in  making  superphosphates. 

Mineral  phosphates,  both  because  of  their  hardness  and 
of  the  presence  of  other  minerals,  which  are  attacked  by 
the  acid,  are  less  easily  dissolved,  and  require  more  acid  in 
proportion  to  the  phosphate  present  than  those  from 
organic  sources.  They  are  also  less  absorbent,  preventing 
the  acid  from  permeating  the  mass  of  the  material,  and 
hence  it  is  more  difficult  to  secure  good  condition  when 
sufficient  acid  is  used  to  dissolve  the  phosphate.  In 
making  superphosphates  from  these  materials,  less  acid  is 
used  than  is  required  to  completely  dissolve  the  phos- 
phates, and  there  is,  therefore,  always  present  in  them 
more  or  less  of  the  insoluble  phosphoric  acid. 

In  the  case  of  animal  bone,  too,  less  sulfuric  acid  is  used 
than  is  required  to  completely  dissolve  the  phosphoric 
acid.  Otherwise,  a  gummy,  sticky  product  would  result, 
due  largely  to  the  organic  matter  in  the  bone.  The  insolu- 
ble phosphoric  acid  in  bone,  bone-black  and  bone-ash 


Superphosphates  —  Potash  87 

superphosphates  is,  however,  of  greater  value  than  the 
insoluble  in  the  mineral  phosphates,  for  reasons  already 
given. 

In  superphosphates,  also,  there  is  nearly  always  present 
a  greater  or  less  amount  —  depending  upon  the  material 
—  of  the  second  form  of  phosphoric  acid,  the  dicalcic, 
reverted  or  retrograde.  This  form  usually  exists  in  the 
greatest  amounts  in  those  made  from  mineral  phosphates, 
which  is  believed  to  be  due  either  to  the  soluble  acting 
upon  the  insoluble  portions,  or  to  the  presence  of  oxide  of 
iron  and  alumina,  which  combine  with  a  portion  of  the 
soluble  phosphoric  acid.  The  soluble  goes  back  to  the 
less  soluble  dicalcic  form. 

Aikman  states  the  matter  very  clearly  in  the  following 
words : 1  "A  change  which  is  apt  to  take  place  in  super- 
phosphate after  its  manufacture  is  what  is  known  as 
'reversion  of  the  soluble  phosphate/  Thus  it  is  found 
that  on  keeping  superphosphate  for  a  long  time  the  per- 
centage of  soluble  phosphate  becomes  less  than  it  was  at 
first.  The  rate  at  which  this  deterioration  of  the  super- 
phosphate goes  on  varies  in  different  samples.  In  a  well- 
made  article,  it  is  practically  inappreciable,  whereas  in 
some  superphosphates,  made  from  unsuitable  materials, 
it  may  form  a  considerable  percentage.  The  causes  of  this 
reversion  are  two-fold.  For  one  thing,  the  presence  of 
undecomposed  phosphate  of  lime  may  cause  it.  This 
source  of  reversion,  however,  is  very  much  less  important 
than  the  other,  which  is  the  presence  of  iron  and  alumina 
in  the  raw  material.  When  a  soluble  phosphate  reverts, 
what  takes  place  is  the  conversion  of  the  monocalcic 
phosphate  into  the  dicalcic. 

"Where  reversion  is  due  to  the  presence  of  iron  and 

1 "  Manures  and  Manuring." 


88  Fertilizers 

alumina  in  the  raw  material,  the  nature  of  the  reaction  is 
not  well  understood,  and  is,  consequently,  not  so  easily 
demonstrated  as  in  the  former  case.  Where  iron  is  present 
in  the  form  of  pyrites,  or  ferrous  silicate,  it  does  not  seem 
to  cause  reversion.  It  is  only  when  it  is  present  in  the 
form  of  oxide  (and  in  most  raw  phosphatic  materials  it  is 
generally  in  this  form)  that  it  causes  reversion  in  the 
phosphate." 

Aikman  also  discusses  the  value  of  reverted  phosphates, 
showing  the  estimation  in  which  they  are  held  in  England  : 
"The  value  of  reverted  phosphate  is  a  subject  which  has 
given  rise  to  much  dispute  among  chemists.  That  it  has  a 
higher  value  than  the  ordinary  insoluble  phosphate  is  now 
admitted,  but  in  this  country,  in  the  manure  trade,  this  is 
not  as  yet  recognized.  At  first  it  was  thought  that  it  was 
impossible  to  estimate  its  quantity  by  chemical  analysis. 
This  difficulty,  however,  has  been  overcome,  and  it  is 
generally  admitted  that  the  ammonium  citrate  process 
furnishes  an  accurate  means  of  determining  its  amount. 
Both  on  the  continent  and  in  the  United  States  reverted 
phosphate  is  recognized  as  possessing  a  monetary  value  in 
excess  of  that  possessed  by  the  ordinary  insoluble  phos- 
phates. The  result  is,  that  raw  mineral  phosphates  con- 
taining iron  and  alumina  to  any  appreciable  extent  are 
not  used  in  this  country,  although  they  do  find  a  limited 
application  in  America  and  on  the  continent." 

As  stated  by  Aikman,  the  reverted  phosphoric  acid  due 
to  the  presence  of  undecomposed  phosphate,  as  well  as 
the  reverted  due  to  the  presence  of  iron  and  alumina,  are 
recognized  by  the  chemists  in  this  country,  and  this 
recognition  is  strongly  encouraged  by  commercial  interests, 
because  of  the  fact  that  our  mineral  phosphates  contain, 
as  a  rule,  iron  and  alumina,  which  by  their  action  reduce 


Superphosphates  —  Potash  89 

the  percentage  of  the  soluble.  The  method  of  chemical 
analysis  which  has  been  adopted  by  the  American  Associa- 
tion of  Official  Agricultural  Chemists  recognizes  this  form, 
and  it  is,  therefore,  determined  and  included  in  the  "  total 
available"  in  statements  of  analysis.  In  one  state,  New 
Jersey,  the  law  requires  that  the  dicalcic  form  only  shall 
be  recognized,  and  it  assumes  that  the  agricultural  value 
of  this  form  is  equal  to  that  of  the  soluble. 

DOUBLE  SUPERPHOSPHATES 

In  addition  to  the  superphosphates  made  directly  from 
the  various  materials  mentioned,  a  special  substance, 
called  a  "double  superphosphate,"  which  may  be  made  by 
dissolving  low-grade  phosphates  with  an  excess  of  dilute 
sulfuric  acid,  or  those  too  poor  in  phosphoric  acid  to  make 
a  high-grade  superphosphate.  The  dissolved  phosphoric 
acid  thus  obtained,  together  with  the  excess  of  sulfuric 
acid,  are  separated  from  the  insoluble  materials  by  filter- 
ing, which  acids,  after  concentration,  are  then  used  for 
dissolving  the  better  phosphates;  and  because  the  acids 
used  for  dissolving  the  phosphates  contain  phosphoric 
acid,  the  content  of  available  phosphoric  acid  in  these 
products  is  more  than  double  that  contained  in  the  ordinary 
products.  These  are  mostly  manufactured  in  Europe,  and 
are  not  used  to  any  extent  in  this  country.  They  possess 
the  advantage  of  containing  a  minimum  of  impurities  and 
a  maximum  of  phosphoric  acid  in  a  soluble  form. 

In  stating  the  composition  of  superphosphates,  the  three 
forms  of  phosphoric  acid  are  all  recognized.  The  sum  of 
the  soluble  and  reverted  forms  is  called  the  "total  avail- 
able," because  these,  as  already  stated,  are  regarded  as 
immediately  useful  to  the  plant.  In  commercial  trans- 


90  Fertilizers 

actions  in  mineral  superphosphates,  the  total  available 
only  is  regarded,  —  the  content  of  insoluble  being 
ignored. 

CHEMICAL  COMPOSITION   OF  SUPERPHOSPHATES 

As  already  stated,  the  composition  of  the  superphos- 
phates varies  according  to  the  richness  in  phosphoric  acid 
of  the  phosphates  used,  and  according  to  the  character  of 
the  material.  Bone-ash  and  bone-black  superphosphates 
are  more  uniform  in  composition  than  those  derived  from 
the  mineral  phosphates,  and  the  phosphoric  acid  is  practi- 
cally all  in  the  soluble  form.  They  contain  on  the  average 
about  16  per  cent  of  total  available  phosphoric  acid.  The 
mineral  or  rock  superphosphates  differ  from  these  in  being 
more  variable  in  their  total  content  of  available,  and  in 
showing  wider  variations  in  the  proportions  of  reverted, 
the  latter  depending  upon  the  skill  in  manufacture,  as 
well  as  the  character  of  the  original  material.  Well-made 
South  Carolina  rock  superphosphates  contain  from  12  to 
14  per  cent  of  total  available,  of  which  1  to  3  per  cent  is 
dicalcic,  or  reverted.  There  are  several  grades  of  the 
Florida  rock  superphosphates,  due  to  the  variation  in  the 
composition  of  the  various  raw  phosphates.  The  pebble 
superphosphates  are  the  richest,  often  containing  as  high 
as  16  or  17  per  cent  of  total  available,  with  varying 
percentages  of  reverted  and  insoluble.  The  Tennessee 
superphosphates  also  vary  from  the  same  cause,  the  richest 
showing  as  high  as  16  to  18  per  cent  of  total  available. 
The  concentrated,  or  double,  superphosphates  may  contain 
as  high  as  45  per  cent  of  available,  practically  all  of  which 
is  soluble.  The  superphosphates  made  from  animal  bone 
are  usually  more  variable  in  their  composition  than  those 


Superphosphates  —  Potash  91 

from  bone-black,  bone-ash  or  mineral  phosphates,  and  the 
variation  is  due  both  to  the  variability  of  the  raw  materials 
and  the  difficulties  involved  in  their  change  into  super- 
phosphates. The  usual  guarantee  on  an  animal  bone 
superphosphate  is  12  per  cent  available,  and  from  3  to  5 
per  cent  of  insoluble.  These  superphosphates  also  differ 
from  the  mineral  superphosphates  in  containing  nitrogen 
in  addition  to  their  phosphoric  acid.  They  are,  therefore, 
really  ammoniated  superphosphates. 

Well-made  superphosphates  contain  no  free  acid. 

In  the  earlier  history  of  the  use  of  acid  phosphates,  or 
rock  superphosphates,  objections  were  urged  against 
them,  and  are  to  some  extent  at  the  present  time,  because 
of  the  supposed  deleterious  effects  of  the  acids  contained  in 
them,  and  these  objections  were  undoubtedly  encouraged, 
—  certainly  not  discouraged,  —  by  those  manufacturers 
who  used  only  genuine  bone  superphosphates.  While  the 
objections  on  this  ground  may  have  had  some  basis  in 
earlier  times,  before  their  manufacture  was  well  under- 
stood, there  can  be  no  rational  objection  to  their  use  at  the 
present  time,  when  they  are  properly  made ;  for  while  in 
fresh  superphosphates  a  portion  of  the  phosphoric  acid 
may  be  in  the  form  of  "free"  phosphoric  acid,  this  form  in 
ordinary  superphosphates  is  practically  all  combined  with 
lime  or  other  minerals  before  it  is  placed  upon  the  market, 
and  there  is  really  no  more  "free"  acid  in  the  rock  super- 
phosphate than  in  any  other.  It  is  quite  likely  this 
erroneous  impression  arose  from  the  fact  that  strong  sul- 
furic  acid  was  used  in  the  manufacture,  and  the  belief 
existed  that  it  remained  as  such.  No  free  sulfuric  acid 
exists  in  well-made  superphosphates.  The  sulfuric  acid  is 
combined  with  the  lime  to  form  gypsum,  as  already  de- 


92  Fertilizers 

scribed,  and  the  free  phosphoric  acid  combines  with  the 
lime  to  form  either  a  soluble  or  a  reverted  form. 

Phosphoric  acid  remains  in  the  soil  until  taken  out  by  plants. 

The  phosphoric  acid  in  superphosphates,  though  soluble 
in  water,  is  not  readily  washed  from  the  soil.  The  real 
object  of  making  it  soluble  is  to  enable  its  better  distribu- 
tion. If  it  were  possible  to  as  cheaply  prepare  the  dicalcic 
or  reverted  form  as  the  soluble,  it  would,  perhaps,  be  quite 
as  useful  from  the  standpoint  of  availability.  After  the 
soluble  is  distributed  in  the  soil,  it  is  fixed  there  by  com- 
bining with  the  lime  and  other  minerals  present.  It  is 
believed  that  it  assumes,  first,  by  the  larger  relative  pro- 
portion of  lime  usually  present  in  soils,  the  dicalcic  form, 
though  it  is  not  positively  certain  that  in  the  present  of  an 
abundance  of  lime,  or  that  in  time,  it  may  not  assume  the 
insoluble  tricalcic  form.  The  soluble  phosphoric  acid  may 
also  combine  with  the  iron  and  alumina  in  the  soil,  and 
form  phosphates  of  these  elements,  though  recent  investi- 
gations lead  to  the  conclusion  that  these  conditions  are 
much  more  rare  than  was  at  one  time  supposed.  The 
time  required  for  the  fixing  of  the  phosphoric  acid,  as  well 
as  the  form  it  may  eventually  assume,  depends  chiefly 
upon  the  character  and  composition  of  the  soil.  In  those 
rich  in  lime,  the  fixation  is  most  rapid,  though  in  no  sense  is 
the  fixation  immediate,  and  in  such  soils  the  fixation  is 
probably  largely  completed  in  the  course  of  a  week.  On 
clay  soils,  containing  a  low  percentage  of  lime,  and  in  light 
soils  that  contain  little  clay  or  organic  matter,  the  fixation 
is  much  slower,  though  even  in  these  the  chances  are  that 
no  serious  loss  of  phosphoric  acid  occurs.  Seldom  do  we 
find  more  than  traces  of  phosphoric  acid  in  drainage  waters, 
even  when  heavy  applications  of  soluble  phosphoric  acid 


Superphosphates  —  Potash  93 

are  followed  by  heavy  rains.  The  fact  that  the  fixing 
power  of  soils  practically  prevents  the  loss  of  phosphoric 
acid  should,  however,  not  be  used  as  an  argument  in  favor 
of  the  careless  use  of  superphosphates. 


POTASH  SALTS 

Until  the  discovery  of  the  mines  of  crude  potash  salts  in 
Stassfurt,  Germany,  in  1859,  and  which  have  been  worked 
since  1862,  the  chief  source  of  potash  for  farm  plants,  other 
than  that  contained  in  farmyard  manures,  was  wood-ashes. 
The  supply  from  this  source  now,  however,  is  sufficient  to 
meet  all  immediate  as  well  as  future  demands,  since  the 
deposits  are  practically  inexhaustible,  though  notwith- 
standing the  abundance  of  the  supply  and  the  improve- 
ments made  in  the  methods  of  utilizing  the  various  salts, 
other  than  potash,  contained  in  the  deposits,  it  is  the  only 
fertilizer  constituent  which  has  remained  practically  con- 
stant in  price  during  the  past  fifteen  years.  In  this  period 
not  only  have  wide  fluctuations  occurred  in  prices  of  nitro- 
gen and  phosphoric  acid  from  the  different  sources,  but 
they  are  much  lower  now  than  formerly. 

The  importance  of  potash  as  a  constituent  of  fertilizers. 

It  has  been  attested  that  potash  is  of  relatively  less 
importance  than  either  nitrogen  or  phosphoric  acid,  inas- 
much as  good  soils  are  naturally  richer  in  this  element,  and 
because  a  less  amount  is  removed  in  general  farming  than 
of  either  nitrogen  or  phosphoric  acid,  as  the  potash  is 
located  to  a  less  extent  in  the  grain  than  in  the  straw, 
which  is  retained  upon  the  farm.  It  is,  however,  a  very 
necessary  constituent  of  fertilizers,  being  absolutely  essen- 
tial for  those  intended  for  light,  sandy  soils  and  for  peaty 


94  Fertilizers 

meadow  lands,  as  well  as  for  certain  potash-consuming 
crops,  as  potatoes,  tobacco  and  roots,  since  these  soils  are 
very  deficient  in  this  element,  and  the  plants  mentioned 
require  it  in  larger  proportion  than  do  others.  In  fact, 
it  is  believed  by  many  careful  observers  —  and  the  belief 
has  been  substantiated  in  large  part  by  experiments 
already  conducted  —  that  the  average  commercial  fer- 
tilizer does  not  contain  a  sufficient  amount  of  this  element. 
It  is  a  particularly  useful  constituent  element  in  the  build- 
ing up  of  worn-out  soils,  because  contributing  materially 
to  the  growth  of  the  nitrogen-gathering  legumes,  an 
important  crop  for  this  particular  purpose. 

Forms  of  potash. 

Potash,  as  has  already  been  stated  in  the  discussion  of 
phosphoric  acid  and  nitrogen,  exists  in  various  forms,  but 
it  differs  from  the  other  elements  in  that  its  chemical  form 
or  combination  seems  to  exert  but  relatively  little  influ- 
ence upon  the  availability  of  the  constituent.  For  exam- 
ple, it  may  be  in  the  form  of  a  muriate  or  chlorid,  of  a 
sulfate  or  of  a  carbonate,  and  while  there  is  a  difference  in 
the  diffusibility  of  these  different  compounds,  —  that  is, 
a  difference  in  the  rate  at  which  they  will  distribute  in  the 
soil  before  becoming  fixed,  —  there  seems  to  be  very  little 
difference  in  the  rate  of  the  absorption  of  the  potash  by  the 
plant.  Nevertheless,  the  form  of  potash  must  be  ob- 
served, because  of  the  possible  influence  that  the  substances 
with  which  it  combines  may  exert  in  reducing  the  market- 
able quality  of  the  crop  to  which  it  is  applied.  This 
influence  has  been  very  distinctly  observed,  particularly  in 
the  growing  of  tobacco,  sugar-beets  and  potatoes,  and  it 
has  been  shown  that  the  potash  in  the  form  of  a  chlorid 
(or  muriate)  does  exert  a  very  deleterious  effect,  especially 


Superphosphates  —  Potash  95 

on  tobacco.  In  fact,  tobacco  manures  should  not  contain 
potash  in  the  form  of  a  muriate.  For  such  crops  as  the 
various  clovers,  Indian  corn  (maize)  and  the  various 
grasses,  no  particular  difference  has  been  observed,  and  the 
form  of  potash  that  may  be  procured  at  the  lowest  price 
per  pound  of  the  constituent  is  the  one,  other  things  being 
equal,  to  use  for  these  crops. 

Kainit. 

In  the  next  place,  the  potash  salts  that  may  be  obtained 
are  divided  into  two  classes :  first,  the  crude  products  of 
the  mines,  and  second,  the  manufactured  products.  Of 
the  crude  products,  kainit  is  the  one  more  largely  used  in 
this  country  than  any  other.  The  potash  contained  in  it 
is  practically  all  in  the  form  of  muriate  or  chlorid.  It  is  a 
compound  of  chlorid  of  potassium  and  sulfate  of  magne- 
sium associated  with  about  30  per  cent  of  common  rock 
salt  or  sodium  chlorid.  It  is  really  a  mixture  varying  in 
composition  according  to  the  mines  from  which  it  is  ob- 
tained. It  is  generally  sold  in  its  natural  state  for  ferti- 
lizer purposes,  although  a  large  part  of  the  output  of  true 
kainit  is  used  in  the  manufacture  of  sulfate  of  potash.  The 
commercial  product  is  guaranteed  to  contain  12  per  cent 
of  actual  potash.  Because  of  its  low  content  of  potash  as 
compared  with  the  manufactured  products,  the  cost  of 
the  actual  potash  is  usually  greater  than  in  these,  owing 
to  the  increased  cost  of  shipping  and  handling  per  unit  of 
potash.  It  is  more  generally  used  near  the  sources  of 
supply,  rather  than  at  a  distance,  unless  the  substances,  as 
ordinary  salt,  also  exert  a  beneficial  indirect  influence  upon 
the  soil,  as  is  very  frequently  the  case.  It  is  not  advisable 
to  apply  it  immediately  preceding  the  planting,  nor  in  the 
hill  or  row,  because  of  the  danger  to  the  young  plant  from 


96  Fertilizers 

the  excess  of  both  the  chlorids  of  sodium  and  magnesium, 
which  are  injurious  to  the  tender  rootlets.  Where  its  use 
is  intended  to  benefit  the  immediate  crop,  it  should  be 
applied  a  considerable  time  before  the  crop  is  planted,  in 
order  that  it  may  be  well  distributed,  and  that  a  portion 
of  the  chlorids,  which  are  extremely  soluble,  may  be  washed 
into  the  lower  layers,  or  into  the  drains. 

Hardsalt. 

This  is  another  crude  potash  salt  which  is  imported  for 
fertilizer  purposes.  Its  composition  is  very  much  like 
kainit  except  that  it  contains  more  water  in  combination. 
It  is  a  mixture  of  chlorid  of  potassium,  sulfate  of  mag- 
nesium and  chlorid  of  sodium.  The  commercial  product 
sold  in  the  United  States  is  guaranteed  to  contain  16  per 
cent  of  actual  potash.  Its  use  as  a  fertilizer  is  the  same  as 
that  of  kainit. 

Carnallit. 

Carnallit  is  of  practical  importance  as  a  fertilizer  only 
in  localities  not  far  distant  from  the  mines  and  is  men- 
tioned because  it  is  the  chief  source  of  muriate  of  potash 
and  other  concentrated  potash  salts.  It  is  really  a  double 
compound  of  muriate  of  potash  and  magnesium  chlorid 
and  has  associated  with  it  large  quantities  of  common 
rock  salt  and  kieserit,  which  is  sulfate  of  magnesia,  and 
other  minerals.  It  contains  about  9  per  cent  of  actual 
potash  and  has  the  property  of  absorbing  large  quantities 
of  water. 

Muriate  of  potash. 

Of  the  more  concentrated  potash  salts,  muriate  of  potash 
manufactured  from  carnallit  is  by  far  the  most  common 


Superphosphates  —  Potash  97 

and  most  generally  used.  It  varies  somewhat  in  composi- 
tion, according  to  the  method  of  manufacture,  though 
practically  only  three  grades  are  met  with  in  this  country 
and  only  one  of  these  is  used  to  any  great  extent  for  agri- 
cultural purposes.  These  grades  are : 

Basis  98  per  cent  pure  .  .  contains  61.9  per  cent  actual  potash 
Basis  95  per  cent  pure  .  .  contains  60.0  per  cent  actual  potash 
Basis  80  per  cent  pure  .  .  contains  50.5  per  cent  actual  potash 

The  last  grade  is  most  common,  and  because  it  absorbs 
moisture  is  guaranteed  to  contain  48  per  cent  actual 
potash,  though  the  absorption  of  water  makes  little  differ- 
ence because  it  occurs  after  the  material  is  placed  in  the 
bag  and  hence  the  correct  amount  is  contained  even  if  it 
is  slightly  diluted.  The  chief  impurities  of  muriate  of 
potash  (chlorid)  are  common  salt,  or  sodium  chlorid,  and 
insoluble  matter,  which  are  not  deleterious  substances. 
The  lower  the  content  of  potash,  the  higher  the  content  of 
impurities,  though  in  all  cases  this  form  of  potash  is  sold 
upon  the  basis  of  80  per  cent  muriate. 

High-grade  sulfate  of  potash. 

High-grade  sulfate  of  potash  is  manufactured  and  used 
in  much  smaller  quantities  than  muriate.  It  is  made 
from  muriate  and  kieserit  at  the  present  time,  though 
formerly  was  manufactured  exclusively  from  kainit.  The 
commercial  product  contains  from  47  to  52.7  per  cent  of 
actual  potash,  or  about  90  to  96  per  cent  of  pure  sulfate  of 
potash,  though  the  most  common  grade  contains  48  per 
cent  of  actual  potash.  It  naturally  varies  somewhat  in  its 
composition,  owing  to  impurities,  either  introduced  or 
imperfectly  removed.  It  is,  however,  regarded  as  prefer- 
able to  the  muriate  for  some  crops,  for  reasons  already 


98  Fertilizers 

given  (page  94),  in  spite  of  its  slightly  greater  cost.  It  is 
rather  less  diffusible  than  the  muriate,  though  it  is  not 
inferior  to  it  as  a  source  of  actual  potash. 

Double  manure  salt. 

Double  manure  salt,  or  double  sulfate  of  potash  and 
magnesia,  is  a  product  obtained  by  refining  kainit  by 
recrystallization.  Though  it  contains  less  potash,  it  is 
similar  in  its  effects  to  the  high-grade  sulfate  of  potash, 
because  it  contains  no  chlorids,  and  is  free  from  other  dele- 
terious substances.  In  many  cases  the  25  per  cent  of 
sulfate  of  magnesium  with  which  it  is  associated  is  believed 
to  be  of  considerable  service.  The  potash  contained  in  it 
is  equivalent  to  25  to  26  per  cent  actual  potash.  The  cost 
of  potash  in  this  material  is  greater  than  in  the  muriate. 

Potash  manure  salt. 

Potash  manure  salt  is  a  term  used  to  designate  a  low- 
grade  muriate  of  potash  containing  20  per  cent  of  actual 
potash.  It  may  be  employed  in  a  manner  similar  to  the 
use  of  muriate  of  potash.  It  must  be  remembered,  how- 
ever, that  the  potash  contained  is  in  the  form  of  a  chlorid, 
and  that  other  impurities  including  sulfate  and  chlorid 
of  magnesium,  common  salt  and  a  few  other  compounds 
are  associated  with  it. 

Double  carbonate  of  potash  and  magnesia. 

This  material  imported  from  Germany  is  a  finely  divided 
powder  containing  about  20  per  cent  of  potash  and  an 
equal  amount  of  magnesia  free  from  chlorids.  On  ac- 
count of  the  small  amount  brought  to  this  country  it  is 
relatively  unimportant. 


PLATE  IV.  —  Mining  and  Composting. 


FIG.  5.  —  MINING  PHOSPHATE  ROCK  BY  HYDRAULIC  PRESSURE. 


FIG.  7.  —  UNLOADING  AND  COMPOSTING  NEW  YORK  STABLE  MANURE 
IN  SOUTH  JERSEY. 


Superphosphates  —  Potash  99 

Potassium  carbonate. 

Potassium  carbonate  is  used  to  some  extent  as  a  fer- 
tilizer and  sometimes  upon  compost  heaps.  Investiga- 
tions show  that  it  is  well  adapted  to  tobacco-growing.  It 
is  a  high-grade  product  containing  65  per  cent  of  actual 
potash. 

Potassium  nitrate. 

This  material  already  mentioned  would  be  especially 
valuable  for  agricultural  purposes  were  it  not  for  its 
greater  value  for  use  in  the  manufacture  of  gunpowder 
and  explosives  which  makes  it  more  expensive  than  the 
combined  cost  of  the  separate  ingredients  in  other  salts. 
It  is  also  called  nitrate  of  potash,  niter  and  saltpeter,  and 
contains  14  per  cent  of  nitrogen  and  44  per  cent  of  actual 
potash. 

Feldspar  and  other  minerals  as  a  source  of  potash. 

Feldspar  and  a  large  number  of  other  minerals  including 
leucite,  alunite,  phonolite  and  nepheline  have  caused 
much  thought  and  experimentation  upon  the  part  of 
chemists  and  investigators  for  a  number  of  years  as  prob- 
able sources  of  potash.  So  far,  little  of  practical  impor- 
tance has  been  accomplished  with  these  minerals  because 
no  methods  have  been  developed  which  would  success- 
fully extract  the  potash,  and  pulverization  even  to  ex- 
treme fineness  does  not  render  potash  contained  in  them 
available. 

Formations  of  alunite  recently  found  at  Marysvale, 
Utah,  caused  considerable  comment  at  the  time  of  their 
discovery ;  but,  here  again,  the  manufacture  is  still  in  the 
experimental  stage.  Nor  has  leucite,  which  contains  18 
to  20  per  cent  of  actual  potash,  been  found  practicable. 


100  Fertilizers 


Seaweeds  as  a  source  of  potash. 

The  flora  of  the  Pacific  Ocean  includes  many  different 
kinds  of  giant  seaweeds  which  grow  luxuriantly  in  the 
coast  waters  from  Alaska  to  Mexico.  The  giant  kelp 
groves  have  attracted  much  attention  as  a  source  of  potash. 
The  ash  of  these  weeds  contains  often  as  high  as  30  per 
cent  actual  potash.  Great  possibilities  are  presented  by 
these  vast  groves  of  seaweed  because  they  may  be  har- 
vested periodically  and  continue  productive.  Up  to  date, 
however,  no  practical  method  has  been  developed  which 
enables  the  harvest  and  preparations  for  market  of  this 
material  at  a  cost  sufficiently  low  to  compete  with  the 
German  products. 

Fixation  of  potash. 

Potash,  like  phosphoric  acid,  is  readily  fixed  in  the  soil, 
though  the  chlorids  with  which  it  is  combined  when  applied 
may  form  soluble  compounds  that  are  readily  leached  from 
the  soil.  For  example,  the  chlorin  combined  with  the 
muriate  may  be  combined  with  lime  or  soda,  forming 
soluble  chlorids  of  lime  or  soda ;  hence,  heavy  applications 
of  muriate  of  potash  may  result  in  the  exhaustion  of  lime 
in  the  soil.  The  fact  that  the  potash  is  fixed,  and  that  the 
chlorids  remain  soluble,  enables  the  application  of  a  large 
quantity,  which  might  otherwise  be  injurious.  That  is,  if 
muriate,  of  potash  is  applied  a  considerable  time  before  the 
crop  that  may  be  injured  by  excess  of  chlorids  is  planted, 
the  chlorids  are  washed  out,  while  the  potash  remains. 

Another  point  of  importance  should  be  observed  in  this 
connection :  the  rapidity  of  fixation  on  many  soils,  espe- 
cially those  of  an  alluvial  character,  which  explains  the 
recommendations  frequently  made  to  apply  potash  salts 


Superphosphates  —  Potash  101 

broadcast  and  immediately  cultivate  in,  otherwise  the 
fixation  would  take  place  at  points  of  contact,  and  the 
distribution  be  incomplete. 

While  it  is  true  that  potash  salts  readily  become  fixed 
in  soils,  it  is  also  true  that  on  light,  sandy  soils,  which  are 
greatly  deficient  in  silt,  clay  and  vegetable  matter,  they 
may  be  subject  to  moderate  leaching  and  slight  loss  into 
the  drainage  water.  Where  irrigation  is  practiced  on  such 
soils  the  probability  of  such  leaching  is  even  greater.  In 
either  case  caution  should  be  exercised  in  their  use. 


CHAPTER  VI 
MISCELLANEOUS  FERTILIZING  MATERIALS 

IN  addition  to  the  specific  fertilizer  materials  described 
in  the  previous  chapters,  which  constitute  the  standard 
sources  of  supply,  a  number  of  other  products  exist,  and 
should  be  considered  here.  Certain  of  these  may  serve 
in  the  manufacture  of  fertilizers,  and  certain  others,  which 
are  not  suitable  for  this  purpose,  may  be  used  to  advantage 
either  because  they  furnish  the  constituents  in  consider- 
able quantities,  or  in  other  ways  assist  in  improving  the 
fertility  of  the  soil.  They  are  often  a  cheap  source  of 
nitrogen,  phosphoric  acid  or  potash,  besides  contributing 
toward  "condition"  of  soil,  which  exercises  a  decided  in- 
fluence in  making  possible  the  best  use  of  commercial 
fertilizers. 

Furthermore,  while  a  consideration  of  these  products 
may  not  be  regarded  as  strictly  pertaining  to  the  subject 
of  commercial  fertilizers,  a  discussion  of  them  is  valuable, 
in  order  that  certain  impressions  now  existing  concerning 
them  may  be  corrected.  These  impressions,  while  not 
entirely  erroneous,  are  not  wholly  in  accord  with  scientific 
facts,  particularly  as  to  how  far  they  may  be  substituted 
for  the  better  products ;  and  on  this  point  information  as 
full  and  exact  should  be  had  as  the  limited  knowledge  that 
we  have  of  the  subject  will  permit.  These  various  products 
cannot  be  strictly  classified  into  the  three  main  groups : 
nitrogenous,  phosphatic  and  potassic.  They  are,  as  a  rule, 

102 


Miscellaneous  Fertilizing  Materials  103 

rather  general  in  their  effect ;  they  contain  small  amounts 
of  all  the  essential  constituents  rather  than  large  amounts 
of  one  or  two,  and  many  of  them  are  useful,  because  of 
their  indirect  action. 

Tobacco  stems  and  stalks. 

Tobacco  stems  consist  of  the  waste  stems  or  ribs  of  the 
leaves,  and  parts  of  the  leaves  themselves,  which  result 
from  the  stripping  of  tobacco  for  the  manufacture  of  cigars, 
or  for  smoking  and  chewing  tobacco.  The  stalks  in- 
clude the  main  stem  and  branches  of  the  plant.  The 
stems  are  frequently  ground  and  sold  as  a  fertilizer,  and 
the  product  is  valuable  for  its  nitrogen  and  potash  —  the 
nitrogen  ranging  in  content  from  2  to  3  per  cent  and  the 
potash  from  6  to  10  per  cent.  They  contain  but  small 
amounts  of  phosphoric  acid.  The  nitrogen  exists  in 
both  the  nitrate  and  organic  forms.  The  nitrate  form 
constitutes  from  one-third  to  one-half  of  the  total  nitrogen, 
and  its  presence  is  due  both  to  the  fact  that  nitrogen  exists 
as  such  in  the  tobacco  plant,  and  to  the  fact  that  saltpeter 
(nitrate  of  potash)  is  frequently  added  in  order  to  improve 
the  marketable  quality  of  the  lower  grades  of  tobacco. 
The  potash  occurs  largely  in  the  soluble  form,  and  is  free 
from  chlorids.  The  tobacco  stalks  are  somewhat  richer 
in  nitrogen  than  the  stems,  ranging  from  3  to  4  per  cent, 
and  are  poorer  in  potash  —  about  4  to  5  per  cent  of  potash 
—  though  the  forms  of  these  two  constituents  are  similar 
in  the  case  of  both  to  those  contained  in  the  stems.  Both 
stems  and  stalks  may  be  frequently  obtained  in  the 
vicinity  of  towns  where  tobacco  manufacture  is  carried 
on,  and  while  more  variable  in  their  content  of  nitrogen 
and  potash  than  the  ground  stems  and  stalks,  due  largely 
to  the  variations  in  the  content  of  moisture,  they  are  a 


104  Fertilizers 

useful  and  often  a  very  cheap  source  of  nitrogen  and 
potash. 

These  waste  tobacco  products  are  free  from  deleterious 
compounds,  and  for  this  reason  alone  are  highly  valued 
as  a  fertilizer  for  tobacco,  as  well  as  for  small  fruits,  for 
which  they  are  especially  useful,  because  of  their  known 
insecticidal  value.  A  ton  of  tobacco  stems  of  good  quality 
contains  nitrogen  equivalent  to  the  amount  contained  in 
500  pounds  of  nitrate  of  soda,  and  potash  equivalent 
to  the  amount  contained  in  200  pounds  of  high-grade 
sulfate  of  potash.  They,  therefore,  possess  a  distinct 
value  as  a  source  of  these  constituents. 

Tobacco  salts. 

Extracts  of  tobacco  are  becoming  important  for  in- 
secticidal purposes.  In  the  manufacture  of  these  extracts 
there  are  a  number  of  by-products  produced  which  are 
sold  for  fertilizer  purposes.  Various  names  have  been  used 
to  designate  these  products.  The  most  common  are  to- 
bacco ammonia  salt  and  tobacco  potash  salt.  The  former 
contains  about  14  per  cent  of  nitrogen  and  6  per  cent  of 
potash;  the  latter  1  to  2  per  cent  of  nitrogen  and  about 
40  per  cent  of  potash.  In  localities  where  this  industry 
is  extensive,  these  salts  are  of  more  than  ordinary  interest 
because  the  plant-food  contained  in  them  is  in  highly 
available  forms.  The  nitrogen  is  in  the  form  of  nitrate 
and  ammonia,  and  the  potash  is  the  form  of  sulfate  free 
from  chlorid. 

Crude  fish  scrap. 

It  frequently  happens  that  farmers  are  so  situated  as 
to  be  able  to  procure  directly  from  the  fishermen  the  fish 
scrap  from  which  dried  ground  fish  is  made.  Very  large 


Miscellaneous  Fertilizing  Materials  105 

amounts  are  used  in  this  crude  form  in  our  coast  states, 
particularly  New  England  and  the  middle  states.  This 
material,  while  chiefly  valuable  for  its  nitrogen,  is  not  uni- 
form in  its  content  of  fertilizing  contituents,  owing  to 
the  wide  variation  in  the  content  of  moisture,  or  water, 
which  may  range  from  as  low  as  25  to  as  high  as  75  per 
cent.  The  nitrogen,  of  course,  varies  with  the  dry  matter, 
and  ranges  from  2.5  to  8  per  cent.  The  scrap  also  contains 
considerable  amounts  of  phosphoric  acid,  ranging  from  2 
to  6  per  cent.  The  fish  scrap  in  this  form,  too,  is  less  valu- 
able as  a  source  of  nitrogen  than  the  dried  ground  material, 
because  of  its  coarser  condition,  requiring  a  longer  time 
for  decay. 

The  whole  fishes  (menhaden)  are  also  used  either  directly 
or  in  a  composted  form  in  many  instances,  and  the  ex- 
cellent results  obtained  are  mainly  due  to  the  rapidity  of 
decay  of  the  nitrogenous  substances.  The  economical 
purchase  of  these  products  depends  largely  upon  the  judg- 
ment of  the  farmer.  He  should  be  guided  in  determining 
their  value  by  the  amount  of  water  contained  in  them. 
As  they  approach  dryness,  they  become  richer  in  the  con- 
stituents of  fertility.  In  any  case,  products  of  this  sort 
should  be  obtained  at  so  low  a  price  per  ton  as  to  guarantee 
to  the  purchaser  a  maximum  quantity  of  the  fertilizing 
constituents  for  his  money,  when  measured  by  the  market 
value  of  the  materials  of  known  composition. 

For  example,  if  crude  fish  scrap,  which  contains  as  a  mini- 
mum 2.5  per  cent  of  nitrogen,  can  be  purchased  for  $5 
a  ton,  it  will  furnish  nitrogen  at  10  cents  a  pound,  or  at 
two-thirds  the  cost  of  this  element  in  nitrate  of  soda  at 
$48  a  ton.  Besides,  the  scrap  contains  phosphoric  acid 
in  good  forms.  At  this  price,  the  purchaser  could  afford 
to  take  the  risk  incident  to  the  variability  of  the  product. 


106    .  Fertilizers 

Wool  and  hair  waste. 

Wool  and  hair  waste  have  already  been  described  in 
part,  though  more  largely  from  the  manufacturers '  stand- 
point, as  representing  materials  that  may  be  utilized  in 
the  manufacture  of  commercial  fertilizers.  These  prod- 
ucts may  frequently  be  obtained  in  large  quantities  and 
at  a  low  price  per  ton  in  towns  in  which  the  original  prod- 
ucts are  used  in  manufacturing,  and  thus  occur  as  wastes. 
Both  are  extremely  variable  in  their  composition,  the  wool, 
particularly,  being  very  liable  to  change  in  this  respect, 
owing  both  to  the  admixture  of  non-nitrogenous  sub- 
stances, such  as  cotton,  and  to  the  source  of  the  waste 
itself,  whether  it  consists  of  the  clippings  and  tags  from  the 
original  fleece,  or  whether  it  is  in  part  the  manufactured 
product.  Different  samples  show  a  wide  range  in  the 
content  of  nitrogen  and  potash,  from  2  to  10  per  cent  in 
the  former,  and  from  1  to  3  per  cent  in  the  latter.  The 
nitrogen  in  the  waste  is  extremely  slow  in  its  action  in  the 
soil,  though  it  may  be  made  directly  useful,  both  as  an 
absorbent  of  other  wastes,  as  in  liquid  manure,  and  as  an 
ingredient  of  composts.  Excessive  quantities  must  be 
applied  in  order  to  obtain  a  marked  immediate  result. 

The  hair  waste  is  also  variable,  both  on  account  of  the 
content  of  moisture,  as  well  as  the  admixture  with  it  of 
other  substances. 

Lime  often  occurs  as  a  waste  product  in  some  industries, 
and  as  such  it  is  frequently  wet  and  pasty,  and  not  easily 
handled. 

These  wastes,  when  they  can  be  purchased  at  a  low 
price  a  ton,  —  and  frequently  they  may  be  obtained  as 
low  as  two  or  three  dollars,  —  serve  an  excellent  purpose 
as  absorbents,  and  for  use  in  orchards  and  pastures,  or 
in  gradually  building  up  the  fertility  of  poor  soils. 


Miscellaneous  Fertilizing  Materials  107 

Sewage. 

In  recent  years,  great  progress  has  been  made  in  the 
handling  of  sewage  from  cities,  and  there  is  now  a  product 
called  "  sewage  sludge/'  which  is  obtained  in  many  towns, 
as  a  result  of  its  chemical  treatment.  Such  examinations 
as  have  been  made  of  this  product  show  it  to  be  very  poor 
in  the  fertilizing  constituents,  showing  less  than  .20  per 
cent  nitrogen,  .05  phosphoric  acid  and  .05  potash.  It  is 
seldom  worth  the  handling.  The  untreated  sewage  and 
garbage  wastes  are  also  obtainable  in  large  quantities, 
and  while  the  constituents  contained  in  them  act  quickly, 
and  while  they  are  considerably  richer  in  these  than  the 
sludge  wastes,  it  seldom  pays  the  farmer  to  handle  them, 
owing  to  their  offensive  character  and  the  enormous 
amount  of  useless  moisture  contained  in  them. 

A  number  of  state  institutions,  sanatariums,  prisons, 
reform  schools  and  the  like  which  maintain  a  large  number 
of  persons  and  farms  run  in  connection  with  the  insti- 
tution have  not  only  installed  separate  sewage  systems, 
but  they  have  also  equipped  these  systems  in  a  manner 
which  permits  the  use  of  the  sewage  as  a  part  of  irrigation 
systems.  This  practice  of  utilizing  sewage  has  proved 
very  successful  in  a  number  of  instances,  but  the  liquid 
should  not  be  used  as  freely  as  water  and  care  should  be 
exercised  in  its  application. 

Muck  and  peat. 

On  many  farms  there  are  low,  wet  places,  where  the 
conditions  are  favorable  for  the  collection  of  partially  de- 
cayed vegetable  matter.  The  material  thus  formed  is 
called  muck  or  peat.  The  thickness  of  the  deposit,  and 
its  character,  depend  upon  the  time  during  which  it  has 
been  formed,  and  the  character  of  the  climate. 


108  Fertilizers 

Muck  is  used  mainly  as  a  source  of  humus,  and  serves 
an  excellent  purpose  as  an  absorbent  in  cattle  stalls  or 
yards.  Fresh  muck,  while  varying  in  composition  accord- 
ing to  its  source,  may  be  said  to  contain  on  the  average 
75  per  cent  of  water  and  about  .75  per  cent  of  nitrogen, 
and  only  traces  of  potash,  phosphoric  acid  and  lime. 
Air-dry  muck  also  varies  in  composition,  largely  owing  to 
the  different  proportions  of  vegetable  and  mineral  matter 
contained  in  the  different  products,  as  well  as  the  amount 
of  water  absorbed  in  its  dry  state.  The  richer  it  is  in 
vegetable  dry  matter,  the  richer  in  nitrogen.  The  value 
of  the  muck  as  a  source  of  humus  is  measured  by  its  content 
of  nitrogen,  while  its  value  as  an  absorbent  depends  upon 
its  content  of  organic  matter.  It  should  also  be  re- 
membered that  it  is  generally  very  acid  in  character. 
Analyses  show  its  lime  requirement  to  be  as  high  as  four 
tons  calcium  oxide  to  the  acre-foot,  hence  its  use  presup- 
poses the  addition  of  acid  to  the  soil  and  the  necessity  for 
lime  to  correct  this  condition.  The  value  of  muck  for 
either  of  these  purposes  is  further  modified  by  the  labor 
necessary  to  secure  it  in  a  dried  condition.  This  product 
is  of  doubtful  value  as  a  source  of  immediately  available 
nitrogen. 

The  usual  method  of  securing  it  is  to  throw  it  out  of  the 
bed  into  heaps,  and  allow  it  to  dry  before  it  is  used,  either 
upon  the  field  or  in  the  stables.  Where  a  muck  bed  exists 
upon  a  farm,  it  should  first  be  studied  in  reference  to  its 
possible  drainage.  If  it  can  be  drained,  it  is  liable  to  prove 
more  useful  where  it  lies  than  for  the  other  purposes 
mentioned. 

At  the  present  time,  muck  is  air-dried,  bagged  and  placed 
upon  the  market  as  "  humus."  It  is  very  doubtful  whether 
material  of  this  character  can  justly  be  termed  "humus" 


Miscellaneous  Fertilizing  Materials  109 

because  the  amount  of  acid  contained  in  it  is  great  and 
because  it  is  in  a  state  of  slow  decomposition.  It  is  not 
uncommon  to  fortify  it  with  different  proportions  of  ferti- 
lizer materials  such  as  nitrate  of  soda,  acid  phosphate, 
muriate  of  potash  and  the  like.  Whatever  the  process 
of  manufacture,  muck  or  humus  seldom  contains  the 
fertility  elements  in  sufficient  quantity  or  proper  form  to 
warrant  its  purchase  unless  the  price  is  low  and  compares 
favorably  with  the  price  of  city  manure. 

King  crab,  mussels  and  lobster  shells. 

King  crab  is  found  in  considerable  quantities  along  the 
Atlantic  coast,  and  is  not  only  used  directly  as  a  fertilizer, 
but  is  also  dried  and  ground  and  introduced  into  com- 
mercial mixtures.  It  is  a  highly  nitrogenous  product, 
containing  in  the  dry  state  an  average  of  10  per  cent,  with 
traces  only  of  phosphoric  acid.  It  also  possesses  a  high 
rate  of  availability,  though  information  on  this  point  is 
derived  from  the  practical  experience  of  farmers,  rather 
than  from  actual  scientific  test.  It  is  also  used  in  many 
sections  of  New  Jersey  in  its  green  or  fresh  state,  either 
directly  on  the  land  or  in  the  form  of  a  compost,  and  be- 
cause of  its  nitrogenous  character,  and  its  tendency  to 
decay  rapidly,  is  a  valuable  source  of  this  element,  of 
which,  in  its  fresh  state,  it  contains  from  2  to  2.5  per  cent. 

In  certain  sections  of  the  coast  states  farmers  have 
access  to  an  almost  unlimited  supply  of  mussels,  which 
may  be  had  for  the  carting.  Analyses  made  at  the  New 
Jersey  Experiment  Station  show  them  to  contain,  in  their 
natural  state,  a  very  considerable  amount  of  fertilizing 
constituents,  the  nitrogen  reaching  .90  per  cent,  the  phos- 
phoric acid  and  potash  .12  and  .13  per  cent,  respectively, 
and  the  lime  15.84  per  cent.  The  organic  portions  of  the 


110  Fertilizers 

mussels  decay  rapidly,  and  serve  as  a  fairly  good  source  of 
nitrogen;  and  since  this  product  is  twice  as  rich  in  this 
constituent  as  average  yard  manure,  it  is  well  worth  the 
expense  of  handling. 

Lobster  shells  are  also  a  waste  of  considerable  impor- 
tance, since  they  can  be  obtained  at  a  very  low  cost,  often 
for  the  carting.  They  contain,  in  their  dry  state,  an  aver- 
age of  over  4  per  cent  of  nitrogen,  3  per  cent  of  phosphoric 
acid  and  about  20  per  cent  of  lime. 

These  products,  of  course,  are  not  to  be  depended 
upon  for  the  entire  supply  of  constituents  to  crops ;  they 
are  mainly  useful  in  improving  the  natural  quality  of  the 
soil  by  building  it  up  in  vegetable  matter  containing 
nitrogen.  Their  best  use  requires  the  addition  of  the 
minerals  from  other  sources. 

Seaweed. 

Seaweed,  already  referred  to  in  the  discussion  of  potash 
salts,  is  held  in  high  esteem  in  the  coast  states  as  a  manurial 
product.  In  Connecticut,  Rhode  Island  and  New  Jersey, 
the  use  of  seaweed  as  a  fertilizer  is  very  general.  In 
Rhode  Island  the  annual  value  of  the  manure  from  this 
source  has  been  estimated  to  be  as  high  as  $65,000. 

In  its  fresh  state  it  contains  from  70  to  over  80  per  cent 
of  water,  and  is  thus  economically  used  in  that  condition 
only  near  the  shore.  It  is  frequently  spread  out  in  thin 
layers  and  dried,  in  which  condition  it  can  be  profitably 
transported  considerable  distances. 

Seaweeds  of  different  kinds  differ  in  their  content  of 
the  fertilizing  constituents.  Certain  of  them  show  a  rela- 
tively high  content  of  nitrogen,  and  others  of  potash,  and 
they  furnish  more  of  these  constituents  than  of  phosphoric 
acid.  All  seaweeds  contain  considerable  salt,  though  if 


Miscellaneous  Fertilizing  Materials  111 

they  are  not  used  in  too  large  quantities,  no  serious  injury 
is  liable  to  follow.  In  fact,  salt  in  some  instances  is  a 
substance  of  considerable  indirect  manurial  value.  Sea- 
weed manure  is  certainly  worthy  of  consideration  where  it 
can  be  obtained  in  quantity  for  the  expense  of  carting. 

Wood-ashes  and  tanbark-ashes. 

Wood-ashes  contain  potash  in  one  of  the  best  forms, 
and  were,  in  the  early  history  of  manuring,  practically 
the  only  semi-artificial  source  of  this  element.  At  the 
present  time,  however,  the  supply  is  limited,  and  the  aver- 
age content  of  potash  in  the  commercial  article  is  much 
lower  than  was  formerly  the  case. 

The  pure  ash  is  not  a  uniform  product.  That  from  the 
different  varieties  of  wood  varies  in  composition.  As  a 
rule,  the  softer  woods  are  poorer  and  the  hard  woods  richer 
in  potash  than  the  average,  the  range  being  from  16  to 
40  per  cent. 

Ashes  also  contain  lime  in  large  quantities,  while  phos- 
phoric acid  is  contained  in  much  smaller  quantities. 
Wood-ashes,  as  usually  gathered  for  market,  however, 
contain  very  considerable  proportions  of  moisture,  dirt, 
and  the  like,  which  cause  a  variability  in  composition 
not  due  to  the  character  of  the  woods  from  which  they 
are  derived.  The  average  analysis  of  commercial  wood- 
ashes  shows  them  to  contain  less  than  6  per  cent  of  potash, 
2  of  phosphoric  acid  and  32  per  cent  of  lime.  Leached 
wood-ashes  contain  on  the  average  30  per  cent  of  moisture, 
1.10  of  potash,  1.50  of  phosphoric  acid  and  29  per  cent 
of  lime  and  2  to  5  per  cent  of  magnesium  oxide. 

Ashes  are  probably  one  of  the  best  sources  of  potash 
that  we  have,  so  far  as  its  form  and  combination  are  con- 
cerned, being  in  a  very  fine  state  of  division,  and  in  such 


112  Fertilizers 

a  form  as  to  be  immediately  available  to  plants.  Ashes 
also  have  a  very  favorable  physical  effect  upon  soils,  the 
lime  present,  of  course,  aiding  in  this  respect.  Canada 
is  now  the  main  source  of  wood-ashes,  the  substitution  of 
coal  for  wood  making  the  supply  in  this  country  for 
commercial  purposes  very  limited.  Owing  to  the  vari- 
ability of  this  product,  it  should  always  be  bought  sub- 
ject to  analysis,  and  to  a  definite  price  a  pound  for  the 
actual  constituents  contained  in  it,  which  should  not 
be  greater  than  the  price  at  which  the  same  constituents 
could  be  purchased  in  other  quickly  available  forms. 

Because  wood-ashes  have  given  excellent  results,  many 
attempts  have  been  made  to  place  them  on  the  market 
and  to  sell  similar  products  under  the  same  name,  and  it  is 
not  uncommon  to  add  to  wood-ashes  of  low  grade,  fertilizer 
materials  to  fortify  the  product  and  to  sell  it  as  a  high- 
grade  material.  This  is  especially  true  since  the  supply 
has  become  inadequate  to  meet  the  demand;  therefore, 
great  care  should  be  exercised  in  its  purchase. 

Tanbark-ashes  are  much  poorer  in  fertilizing  content  than 
those  obtained  from  the  regular  commercial  sources  of  sup- 
ply. They  seldom  contain  more  than  2  per  cent  of  potash, 
1.5  per  cent  of  phosphoric  acid  and  33  per  cent  of  lime. 

Limekiln-ashes  are  obtained  in  the  burning  of  lime  with 
wood,  and  are  also  relatively  poor  in  potash,  containing 
less  than  1.5  per  cent  of  potash  and  1  per  cent  of  phosphoric 
acid.  The  product  is,  however,  much  richer  in  lime  than 
the  average  wood-ashes,  often  containing  as  high  as  50 
per  cent  of  calcium  oxide. 

Coal-ashes. 

It  is  believed  by  many  that  coal-ashes,  because  of  their 
favorable  effect  upon  many  soils,  also  possess  considerable 


Miscellaneous  Fertilizing  Materials  113 

fertilizing  value,  whereas  analyses  show  them  to  contain 
only  traces  of  soluble  potash  and  of  phosphoric  acid.  The 
good  results  from  their  use  is  undoubtedly  due  to  their 
beneficial  indirect  effect  in  improving  the  physical  charac- 
ter of  heavy  soils. 

Cotton-hull-ashes. 

Cotton-hull-ashes  were  formerly  made  in  considerable 
quantities  in  the  southern  states,  where  the  hulls  were 
used  as  fuel  in  the  furnaces  connected  with  gins  and 
presses.  A  larger  number  of  analyses  of  this  product 
show  it  to  be  exceedingly  variable  in  composition,  rang- 
ing from  12  to  45  per  cent  of  potash,  2  to  12  per  cent 
of  available  phosphoric  acid  and  about  10  per  cent 
each  of  lime  and  magnesia.  They  can  be  safely  pur- 
chased only  on  the  basis  of  their  actual  composition. 
They  are  an  excellent  source  of  potash  and  phosphoric 
acid,  because  free  from  chlorids  and  other  deleterious 
substances,  but  are  not  so  rich  in  lime.  They  are  es- 
pecially useful  for  such  crops  as  are  injured  by  the 
presence  of  chlorids. 

Corn-cob-ashes. 

Corn-cobs  are  a  bulky  by-product  and  accumulate 
rapidly  at  elevators  and  milling  plants.  At  many  of  these 
plants,  the  cobs  are  burned  and  the  ash  sold  for  fertilizer 
purposes.  Pure  corn-cob-ash  thoroughly  burned  often 
contains  as  high  as  40  per  cent  soluble  potash.  The 
average  product  varies  in  content  of  potash  from  6  to 
20  per  cent.  There  is  also  a  trace  of  soluble  phosphoric 
acids.  Because  it  is  so  variable  it  should  be  purchased 
only  upon  guarantee  or  analysis. 


114  Fertilizers 

Cocoa  shells. 

Sometimes  cocoa  shells  are  ground  and  sold  for  fertilizer. 
They  contain  on  the  average  2.5  per  cent  of  nitrogen, 
.75  per  cent  of  phosphoric  acid  and  2.5  per  cent  of  potash. 
They  are  not  considered  a  highly  valuable  source  of 
plant-food. 

Green  sand  marl. 

Marl  may  contain  one  or  more  of  the  constituents, 
phosphoric  acid,  potash  and  lime.  Shell  marls  are  usually 
very  rich  in  lime,  but  contain  only  traces  of  phosphoric 
acid  and  potash.  The  green  sand  marls  of  New  Jersey 
often  contain  very  considerable  amounts  of  phosphoric 
acid  and  potash,  though  they  vary  widely  in  composition. 
They  contain,  on  the  average,  2.20  per  cent  of  phosphoric 
acid,  4.70  per  cent  of  potash,  and  2.90  per  cent  of  lime. 
These  constituents,  particularly  the  potash,  are,  as  a  rule, 
slowly  available. 

Marl,  however,  is  an  important  amendment  to  soils, 
not  only  because  of  its  content  of  mineral  constituents, 
but  because  these  constituents  are  associated  with  prod- 
ucts that  exert  a  very  favorable  mechanical  effect  upon 
soils.  Large  areas  of  land  in  the  state  of  New  Jersey, 
formerly  unproductive,  chiefly  because  of  physical  im- 
perfections, have  been  made  very  productive  mainly 
through  the  application  of  marl. 

The  use  of  marl  is  now  less  general  than  when  the  fer- 
tilizing constituents  from  artificial  sources  were  dearer, 
and  when  the  labor  of  the  farm  was  more  abundant  and 
cheaper.  The  quicker  effect  of  more  soluble  fertilizer 
constituents  has  had  an  influence  in  reducing  the  use  of 
marl  where  quick  returns  are  desirable.  Where  farmers 


Miscellaneous  Fertilizing  Materials  115 

have  deposits  of  marl  upon  their  own  farms,  or  within 
short  distances  of  them,  or  can  secure  it  at  a  low  price, 
its  application  is  a  desirable  method  of  improving  land. 

The  results  from  the  use  of  marl  are  frequently  due  as 
much  to  the  improvement  of  the  physical  condition  of 
soils  as  to  the  fertility  constituents  added.  Marl  may  be 
carted  and  spread  upon  the  land  when  other  work  of  the 
farm  is  not  pressing,  thus  making  it  possible  to  get  a  con- 
siderable addition  of  fertility  at  a  small  expense. 

Agricultural  salt. 

Agricultural  salt  which  is  chiefly  common  salt  or  sodium 
chlorid,  is  frequently  used  as  a  manure.  It  supplies 
no  essential  plant-food  constituent.  Its  value  is  still 
disputed,  though  it  is  admitted  that  where  its  use  is 
favorable,  it  is  due  to  indirect  action  in  aiding  the  decom- 
position of  animal  and  vegetable  matter,  increasing  the 
absorbing  power  of  soils,  and  by  its  reaction  with  lime 
acting  as  a  solvent  for  phosphates.  Its  most  important 
function  is  in  bringing  the  reserves  of  insoluble  potash 
in  the  soil  into  solution. 

Upon  heavy  soils,  the  use  of  common  salt  may  prove 
injurious.  If  carbonate  of  lime  is  present  in  the  soil,  com- 
pounds are  formed  which  deflocculate  clay  and  render  it 
wet  and  sticky. 

In  view  of  the  advantages  enumerated  there  is  no  good 
reason  for  paying  from  $4  to  $6  a  ton  for  this  substance, 
when  practically  the  same  effect  can  be  obtained  from  the 
salt  contained  in  the  crude  potash  salt,  kainit,  one-third 
of  the  total  weight  of  which  is  common  salt.  This,  too, 
may  be  had  free  of  charge,  or  for  the  handling,  as  the 
market  price  of  the  kainit  is  based  upon  its  content  of 
potash. 


116  Fertilizers 

Powder  waste. 

Powder  waste  also  consists  largely  of  common  salt, 
though  frequently  containing  appreciable  percentages 
of  nitrogen  in  the  form  of  a  nitrate.  Its  use  can  only  be 
recommended  when  it  can  be  obtained  at  a  low  price  per 
ton,  or  for  the  handling,  and  upon  soils  that  show  a  marked 
benefit  from  its  application. 

Gas  lime. 

"In  gas  works,  quicklime  is  used  for  removing  the  impuri- 
ties from  the  gas.  Gas  lime,  therefore,  varies  considerably 
in  composition,  and  consists  really  of  a  mixture  of  slaked 
lime,  or  calcium  hydrate,  and  carbonate  of  lime,  together 
with  sulfites  and  sulfides  of  lime.  These  last  are  injurious 
to  young  plant  life,  and  gas  lime  should  be  applied  long 
before  the  crop  is  planted,  or  at  least  exposed  to  the  air 
some  time  before  its  application.  The  action  of  air  con- 
verts the  poisonous  substances  in  it  into  non-injurious 
products.  Gas  lime  contains  on  an  average  40  per  cent  of 
calcium  oxide,  and  usually  a  small  percentage  of  nitrogen." 

Where  it  can  be  used  to  advantage,  its  cost  should,  as 
in  the  case  of  the  other,  be  based  on  the  proportion  of 
actual  lime  present. 

Gypsum  or  calcium  sulfate. 

Gypsum  is  a  sulfate  of  lime,  containing  water  in  com- 
bination. Pure  gypsum  contains  32.5  per  cent  of  lime, 
46.5  per  cent  of  sulfuric  acid  and  21  per  cent  of  water. 

Plaster  of  paris  is  prepared  from  gypsum  by  burning, 
which  drives  off  the  water  it  contains. 

Gypsum,  like  other  forms  of  lime,  furnishes  directly 
the  element  calcium,  and  also  exerts  a  favorable  solvent 
effect  upon  the  soil.  It  was  formerly  used  in  large  quan- 


Miscellaneous  Fertilizing  Materials  117 

tities,  particularly  for  clover,  and  it  is  believed  that  its 
favorable  effect  was  due,  not  so  much  to  the  direct  addition 
of  lime,  as  to  its  action  upon  insoluble  potash  compounds 
in  the  soil,  in  setting  free  potash.  Thus  the  application 
of  plaster  caused  an  increase  in  crop,  because  of  the  potash 
made  available. 

We  have  in  the  eastern  states  two  main  sources  of  gyp- 
sum, namely,  Nova  Scotia  and  Cayuga,  New  York.  Nova 
Scotia  plaster  contains  on  the  average  over  90  per  cent  of 
sulfate  of  lime,  and  is,  therefore,  purer  than  that  obtained 
from  Cayuga,  which  often  shows  as  low  as  65  per  cent 
of  pure  sulfate ;  the  latter,  however,  frequently  contains 
appreciable  amounts  of  phosphoric  acid. 

Phosphorus  powder. 

In  many  places  it  is  possible  to  obtain  plaster  which  is  a 
waste  in  the  manufacture  of  phosphorus.  This  waste 
contains  the  plaster  in  a  precipitated  form,  and  frequently 
also  contains  considerable  amounts  of  phosphoric  acid. 
The  disadvantage  of  this  waste  lies  in  the  fact  that  it  is 
frequently  wet  and  lumpy,  and  thus  not  easily  handled 
and  distributed.  Its  advantage  lies  in  its  content  of 
phosphoric  acid,  which  ranges  from  1.5  to  2  per  cent, 
though  as  a  rule,  it  can  be  purchased  at  a  lower  price  a 
ton  than  that  from  the  regular  sources. 

Calcium  carbide  waste. 

Calcium  carbide  waste  is  a  by-product  obtained  in  the 
manufacture  of  acetylene  gas.  It  is  a  solid  residue  con- 
sisting chiefly  of  calcium  carbonate,  calcium  hydrate  and 
water.  It  is  valuable  as  a  source  of  lime  only  when  it 
may  be  secured  at  an  extremely  low  cost  because  it  is 
usually  wet  or  otherwise  in  very  poor  mechanical  condi- 


118  Fertilizers 

tion.  Unless  it  has  been  thoroughly  exposed  to  the  air, 
it  contains  small  amounts  of  acetylene  gas  which  is  in- 
jurious to  seeds.  It  should  be  exposed  to  the  air  before 
using  or  applied  to  the  soil  a  few  weeks  before  planting. 

Oxy-acetylene  residue. 

Occasionally  oxy-acetylene  residue  is  to  be  had  for 
fertilizer  purposes.  It  is  another  by-product  from  the 
manufacture  of  gas,  but  it  should  not  be  confused  with 
calcium  carbide  waste  because  its  principal  ingredient  is 
potash  rather  than  calcium.  It  contains  from  45  to  55 
per  cent  of  potash  in  the  form  of  the  muriate,  a  high  per- 
centage of  which  is  soluble  in  water. 

Purchase  and  use  of  miscellaneous  materials. 

There  are  a  vast  number  of  miscellaneous  fertilizing 
materials  left  unmentioned  in  the  foregoing.  For  the 
greater  part  such  materials  are  only  used  in  localities 
where  they  may  be  secured  at  little  or  no  cost  outside  of 
the  cost  of  labor  for  hauling  and  distribution.  In  general, 
miscellaneous  materials  are  very  bulky  and  are  not  con- 
centrated in  the  elements  of  plant-food  even  though  the 
constituents  may  be  contained  in  forms  valuable  for  plant- 
feeding  purposes.  In  many  cases  the  indirect  effect  upon 
the  physical  condition  of  the  soil  is  quite  as  valuable  as 
the  plant-food  contained,  as  it  is  the  case  with  green  sand 
marl  so  extensively  used  in  New  Jersey  at  one  time.  The 
same  is  true  of  peat  and  muck.  If  the  material  is  con- 
centrated and  offered  for  sale,  it  is  always  advisable  to 
purchase  only  upon  analysis  or  guarantee.  This  is  true 
in  the  case  of  most  materials  which  may  be  had  at  little 
cost  because  often  they  will  not  return  the  cost  of  carting 
and  handling. 


CHAPTER  VII 
FARMYARD  AND  GREEN-MANURES 

OF  the  many  materials  used  by  the  farmer  for  soil 
improvement,  there  is  no  one  so  thoroughly  appreciated 
as  farmyard  manure.  It  is  a  natural  product  of  the  farm 
and  returned  to  the  land  supplies  humus  and  small 
amounts  of  plant-food  which  assist  materially  in  main- 
taining soil  fertility.  Even  though  the  amount  of  plant- 
food  is  relatively  small  and  poorly  balanced,  its  use  is 
faultless,  almost  never  injurious,  and  the  advantages  are 
easily  apparent. 

The  advantages  of  farmyard  manure,  and  green-manures 
as  well,  are  in  large  measure  the  result  of  indirect  action. 
They  increase  the  water-holding  capacity  of  soils,  improve 
tilth  or  physical  character  and  make  the  soil  a  more 
favorable  medium  for  the  growth  and  development  of 
bacteria  so  pertinent  to  soil  improvement.  Different 
from  green-manures,  farmyard  manure  actually  contains 
these  bacteria.  This  is  one  of  its  greatest  assets. 

In  spite  of  the  many  advantages  of  manure,  little  care 
is  given  it.  The  losses  from  manure  are  enormous  each 
year.  Unfortunately  proper  care  means  considerable  in- 
convenience and  often  an  outlay  of  capital.  When  these 
losses  are  efficiently  checked,  much  greater  results  may 
be  expected. 

119 


120  Fertilizers 

Variations  in  manures. 

Yard  manure  varies  in  its  composition  according  to  the 
character  of  the  animals  producing  it,  the  quality  of  the 
food  and  the  object  of  feeding.  Its  composition  is  also 
influenced  by  the  amount  and  kind  of  litter  used,  and  its 
handling  after  it  is  secured.  The  manure  from  young 
animals  is  less  valuable  than  that  made  when  animals 
are  full  grown.  Manure  made  from  fattening  animals  is 
richer  than  that  produced  by  dairy  cows;  animals  fed 
upon  hay  and  straw  furnish  manure  much  less  valuable 
than  when  the  cereal  grains  constitute  a  part  of  the  ration. 

Manure  produced  by  different  animals. 

Horse  manure  is  richer  in  nitrogen,  contains  less  water 
and  is  less  variable  in  composition  than  that  obtained  from 
cows.  The  manure  made  by  animals  consuming  rich 
food  is  more  liable  to  fermentation  than  that  produced 
when  they  are  fed  upon  bulky  or  watery  feeds. 

Horse  manure  is  called  a  "hot  manure"  because  of  its 
tendency  to  hot  fermentation,  and  is  for  this  reason  par- 
ticularly useful  for  hotbeds,  and  for  forcing  early  growth. 
Cow  manure,  on  the  other  hand,  is  called  a  "  cold  manure," 
because  less  liable  to  fermentation.  Sheep  manure  con- 
tains less  water,  and  is  richer  in  the  fertilizing  constituents 
than  either  horse  or  cow  manure.  Pig  manure,  while 
quite  as  watery  as  cow  manure,  is  richer  in  nitrogen. 

Composition  of  stable  manure. 

Manure  from  horse  stables  in  large  cities  also  varies 
considerably  in  composition.  It  contains  on  the  average 
75  per  cent,  or  1500  pounds  to  the  ton,  of  water,  and  25 
per  cent,  or  500  pounds  to  the  ton,  of  dry  matter,  which 


Farmyard  and  Green-Manures  121 

contains  all  of  the  manurial  ingredients.  The  water  is  of 
no  particular  value ;  it  simply  increases  the  cost  of  han- 
dling. The  dry  matter  consists  of  10  to  12  per  cent  of  ash, 
and  from  12  to  15  per  cent  of  organic  matter.  The  ash 
contains  from  8  to  10  pounds  each  of  phosphoric  acid  and 
lime,  and  6  to  8  pounds  of  potash;  while  the  organic 
matter  contains  from  8  to  10  pounds  of  nitrogen. 

Its  indirect  value,  however,  is  often  quite  as  great  as, 
and  frequently  greater  than,  its  direct  value,  —  first, 
because  of  its  vegetable  matter,  which  materially  improves 
the  absorbing  and  retaining  power  of  soils;  and,  second, 
because  of  the  lower  forms  of  life,  or  bacteria,  contained 
in  it,  which  induce  useful  fermentations  in  the  soil.  Not 
including  the  lime,  the  average  ton  of  city  manure  con- 
tains but  28  pounds  of  actual  fertilizer  constituents. 

Solid  and  liquid  portions. 

The  nitrogen  digested  from  the  food,  as  well  as  a  large 
part  of  the  potash,  is  found  in  the  liquid  portions  of  the 
manure;  while  the  nitrogen  in  the  undigested  portions, 
as  well  as  a  large  part  of  the  phosphoric  acid,  is  contained 
in  the  solid  residue.  The  nitrogen  in  the  urine  is  largely 
in  the  form  of  "urea,"  a  compound  soluble  in  water,  and 
is  easily  decomposed ;  the  potash  is  also  soluble  in  water. 
These  constituents  are,  therefore,  the  most  active. 

Sources  of  loss  in  manures. 

Manures  are  susceptible  to  two  direct  sources  of  loss, 
the  first  of  which  is  due  to  fermentation,  which  results  in 
the  loss  of  nitrogen;  and  the  second  is  due  to  leaching, 
which  may  finally  result  in  a  loss  of  all  of  the  constituents, 
though  it  is  confined  largely  to  the  soluble  nitrogen  and 
potash.  By  fermentation,  the  nitrogen  in  the  manure  is 


122  Fertilizers 

changed  to  ammonia,  usually  in  the  form  of  a  carbonate, 
which  is  volatile,  and  escapes  into  the  atmosphere. 

Care  of  manures. 

Fermentation,  causing  loss,  may  be  prevented  by  keep- 
ing the  manure  moist  and  well  packed.  The  loss  through 
leaching  may  be  stopped  if  the  passage  of  water  through 
it  is  prevented.  The  best  method  to  preserve  it  is  to 
make  it  under  cover,  and  in  pits  made  water-tight;  by 
such  shelter  and  protection,  the  maximum  amount  of 
manurial  value  is  obtained.  The  soluble  constituents  are 
prevented  from  being  washed  into  the  drain,  and  the  loss 
of  volatile  compounds  is  reduced  to  a  minimum.  Where 
it  is  not  practicable  to  have  water-tight  pits,  manure 
should  be  collected  in  yards  that  drain  to  the  center, 
plenty  of  absorbent  used,  drainage  from  the  roof  should 
not  be  allowed  to  run  into  the  yard,  and  the  product 
should  be  removed  to  the  fields  as  often  as  possible. 

Experiments  conducted  to  determine  the  extent  of  the 
loss  of  valuable  constituents  due  to  improper  fermentation 
and  to  leaching  have  shown  that,  under  average  condi- 
tions of  season,  the  loss  from  exposure  for  six  months 
will  range  from  one-third  to  one-half  of  the  total  constit- 
uents. This  loss  falls  upon  the  most  active  forms;  the 
constituents  remaining  in  the  manure  after  being  sub- 
jected to  such  losses  are  the  least  active  and  directly 
useful. 

Manure  preservatives. 

The  loss  of  ammonia,  both  in  the  stables  and  in 
manure  pits,  may  also  be  prevented  by  the  use  of  land 
plaster,  phosphate  rock,  kainit  or  acid  phosphate,  which 
have  the  power  of  fixing  and  retaining  the  volatile  gases. 


Farmyard  and  Green-Manures  123 

A  pound  a  day  to  each  grown  animal,  sprinkled  around 
in  the  stable,  is  sufficient.  The  same  proportion  and 
amount  may  be  used  on  the  manure  heap.  The  value  of 
this  practice  is,  however,  measured  by  the  care  of  the 
manure  afterward,  since  the  fixed  constituents  are  still 
liable  to  loss  by  leaching. 

The  improvement  of  manures. 

Manures  are  improved  as  they  are  reduced  in  bulk, 
and  as  the  constituents  are  made  available  or  directly 
useful;  this  is  accomplished  by  well-regulated  fermenta- 
tion or  rotting.  By  well-regulated  fermentation  is  meant 
that  which  results  in  the  decay  of  organic  matter  with 
the  least  loss  of  nitrogen.  The  loss  from  fermentation  is 
greatest  when  the  manure  lies  in  loose  heaps,  the  access 
of  air  aiding  the  decomposition;  the  loss  is  least  when 
it  is  packed  and  moist.  The  mixing  of  the  manures  of 
the  various  animals,  hot  and  cold,  also  tends  to  reduce 
fermentation. 

If  the  fermentation  becomes  too  active,  great  heat  is 
developed,  which  causes  the  rapid  escape  of  moisture; 
the  manure  is  burned  and  has  a  whitish  and  moldy 
appearance,  —  it  is  called  "fire  fanged."  Under  these 
circumstances  there  is  a  loss  of  nitrogen.  The  "fire- 
fanging"  may  be  prevented  by  keeping  the  heap 
moist. 

It  is  evident,  therefore,  that  the  improvement  of 
manures,  while  it  reduces  the  bulk  and  increases  avail- 
ability of  the  fertilizing  elements,  requires  care  and  labor. 
Whether  such  improvement  will  pay  or  not  depends,  first, 
upon  the  cost  of  labor,  and  second,  upon  the  use  to  which 
the  manure  will  be  put.  Where  labor  is  expensive,  and 
the  manure  is  used  for  the  growing  of  such  gross-feeding 


124  Fertilizers 

crops  as  corn,  the  advantages  derived  are  least.  When 
the  handling  can  be  performed  by  the  regular  labor  of  the 
farm,  and  where  the  manure  is  applied  to  garden  or  quick- 
growing  crops,  the  advantages  are  greatest. 

On  the  whole,  however,  it  is  safe  to  estimate  that  the 
least  labor  necessary  to  get  the  manure  from  the  animal 
to  the  field  is  the  best  policy ;  that  is,  while  there  may  be 
loss,  and  while  the  constituents  may  not  be  so  active, 
still,  the  financial  results  attained  are,  because  of  the 
saving  of  labor,  quite  as  good. 

There  is  another  advantage  in  the  careful  fermentation 
of  manures  which  should  not  be  overlooked,  particularly 
on  soils  poor  in  vegetable  matter;  that  is,  the  develop- 
ment of  useful  bacteria,  the  work  of  which  is  so  important. 
What  has  been  said  of  yard  manure  is  also  true  for  other 
manures  of  the  farm. 

Application  of  yard  manure. 

Two  points  should  be  kept  in  mind  in  the  application 
of  yard  manures,  — first,  that  they  are  essentially  nitrog- 
enous products;  and  second,  that  they  are  particularly 
valuable  because  of  the  useful  ferments  contained  in 
them.  If  too  much  is  added  at  one  time,  a  loss  of  nitro- 
gen is  liable  to  follow,  and  the  benefits  derived  from  the 
ferments  are  limited  to  small  areas.  The  manure  of  the 
farm  should  be  distributed  as  far  as  possible,  and  supple- 
mented by  more  concentrated  materials.  Coarse  manures 
are  better  adapted  for  heavy  lands,  while  those  which  are 
well  rotted  are  more  useful  on  light  soils.  There  should 
be  as  little  handling  of  manure  as  possible,  it  should  be 
carted  daily  when  convenient,  and  uniformly  spread,  pref- 
erably on  plowed  ground  and  thoroughly  worked  into 
the  surface  soil.  (See  Fig.  6.) 


Farmyard  and  Green-Manures 


125 


Poultry  and  pigeon  manures. 

These  products  accumulate  in  considerable  amounts  on 
many  farms,  and  are  often  more  highly  valued  than  their 
composition  warrants.  Many  believe  that  they  can  be 
favorably  compared  with  high-grade  commercial  fertilizers. 
The  good  results  obtained  are  doubtless  due  to  the  readily 


FIG.  6.  —  THE  MANURE  SPREADER  is  A  LABOR-SAVING  DEVICE 

WHICH   SECURES  AN    EVEN    DISTRIBUTION". 


available  form  in  which  the  nitrogen  exists,  since  the 
examination  of  these  products  does  not  show  them  to  be 
particularly  rich  in  nitrogen,  or  in  the  mineral  elements 
of  fertility,  phosphoric  acid  and  potash. 

The  composition  of  chicken  manure  in  the  fresh  state 
is  very  variable  not  only  in  its  content  of  the  fertility  ele- 
ments but  also  in  its  content  of  moisture  which  in  large 
degree  determines  its  value  for  manurial  purposes.  The 
following  table  shows  some  of  its  variations : 


126 


Fertilizers 


PBB 

CENT 

Water 

Nitrogen 

Phos. 
Acid 

Potash 

Fresh 
Cornell  Exp.  Station    . 
Cornell  Exp.  Station    . 
New  Jersey  Exp.  Station 
N.  Y.  State  Station      . 
N.  Y.  State  Station      . 
Mass.  Exp.  Station 
Average                .... 

46.84 
39.67 
55.00 
59.70 
55.30 
45.73 
4987 

1.38 
.75 
1.09 
1.40 
1.14 
.79 
92 

.50 

.22 
.92 
.92 
.72 
.47 
.62 

.41 
.23 
.45 
.32 
.25 
.18 
30 

Air-dried 
N.  Y.  State  Station      .     . 
N.  Y.  State  Station      .     . 
Mass.  Exp.  Station      .     . 

7.44 
7.13 
8.35 
7.64 

1.82 
1.53 
2.13 
1.83 

2.21 
1.92 
2.02 
2.05 

1.11 
1.01 
.94 
1.02 

Where  the  practice  of  storing  chicken  manure  in  a  bin 
or  discarded  corn  crib  is  common,  as  is  so  generally  the 
case  in  small-fruit  and  poultry  farms,  it  is  not  probable 
that  the  moisture  is  as  low  as  in  the  analyses  of  air-dried 
manure  given  above.  It  is  more  likely  to  be  in  the  neigh- 
borhood of  20  per  cent  and  the  percentage  of  the  fertility 
elements  is  relatively  less.  Hence,  even  in  the  best  con- 
dition, these  products  compare  favorably  with  commer- 
cial fertilizers  only  in  their  content  of  nitrogen.  Naturally 
they  also  vary  in  their  composition,  according  to  the  char- 
acter of  food  used  in  their  production. 

Floor  sweepings  from  poultry  houses  are  also  valuable. 
The  kind  and  amount  of  litter  used  is  the  cause  of  wide 
variations  in  the  composition  of  such  material.  In  general, 
it  is  very  dry  and  fine,  hence  capable  of  even  distribution. 

Pigeon  manure  differs  but  little  from  hen  manure  in 
composition,  though  usually  it  is  much  drier  and  some- 
what richer  in  nitrogen. 


Farmyard  and  Green-Manures  127 

These  products  should  be  cared  for,  since  the  constit- 
uents in  them  serve  quite  as  well  in  the  feeding  of  plants 
as  those  contained  in  the  more  concentrated  forms,  though 
a  higher  estimation  should  not  be  placed  upon  the  con- 
stituents than  upon  those  contained  in  commercial  forms 
which  are  quite  as  good. 

It  is  a  good  practice  to  use  phosphate  rock  or  acid  phos- 
phate with  small  amounts  of  muriate  of  potash  or  kainit 
upon  the  dropping  boards.  This  serves  not  only  as  a 
preservative,  but  tends  to  make  the  final  product  a  better 
balanced  fertilizer  mixture. 

Composts. 

In  addition  to  the  yard  manure,  there  are  about  most 
farms  wastes  of  considerable  importance,  weeds,  grasses, 
and  coarse  growths  of  many  kinds,  which  all  contain 
greater  or  less  amounts  of  manurial  constituents.  These 
may  be  utilized  profitably  as  absorbents  in  the  barnyard. 
When  this  method  is  adopted,  the  weeds  should  be  cut 
before  they  have  matured,  or  they  furnish  an  excellent 
means  of  transmitting  weed  seeds.  These  waste  products 
may  also  be  used  in  making  what  are  called  "  composts." 
These,  of  course,  differ  according  to  the  conditions  of  the 
farmer.  Where  peat  or  muck  is  available,  they  are  more 
advantageous  than  where  these  products  are  not  at  hand. 
The  main  object  of  the  compost  heap  is  to  cause  a  more 
rapid  decay  of  such  products,  without  the  loss  of  essential 
constituents.  (See  Fig.  7.) 

A  good  compost  heap  may  be  made  by  placing  a  layer 
of  manure,  then  a  layer  of  weeds  or  waste  products  of 
any  kind,  then  a  layer  of  lime  or  wood-ashes,  the  whole 
well  moistened,  and  the  order  repeated  until  all  of  the 
products  are  used.  The  manure  starts  fermentation,  the 


128  Fertilizers 

lime  or  ashes  aid  in  the  rotting,  prevent  acidity  and  keep 
the  heap  alkaline,  and  the  moisture  prevents  too  hot  fer- 
mentation. By  careful  management  destructive  fermenta- 
tion is  prevented,  the  bulk  is  very  materially  reduced  and 
the  quality  of  the  constituents  greatly  improved.  The 
chief  difficulty  in  the  making  of  composts,  as  well  as  with 
other  methods  used  in  the  improvement  of  manures,  is 
the  expense  of  labor. 

It  pays  to  take  good  care  of,  and  to  save,  manurial 
products,  to  reduce  wastes  and  to  improve  the  quality 
of  the  constituents  by  the  methods  suggested. 

GREEN-MANURES 

A  great  deal  of  misconception  is  prevalent  concerning 
the  value  of  what  are  termed  "green-manures."  These 
do  possess  a  distinct  value,  and  a  proper  understanding 
of  their  place  in  farm  management  will  undoubtedly  re- 
sult in  their  large  and  better  use,  and  in  the  consequent 
improvement  of  agricultural  practice.  By  green-manures 
is  meant  any  crop  that  is  grown  primarily  for  the  purpose 
of  improving  the  soil,  and  not  for  the  harvested  product. 

"Nitrogen  gatherers"  and  "nitrogen  consumers." 

In  this  sense  any  crop  will  serve  as  a  green-manure, 
yet  certain  crops  possess  a  greater  value  than  others  for 
this  purpose,  because  they  are  able  to  obtain  certain  of 
their  constituents  from  sources  not  accessible  to  all  crops. 
In  other  words,  the  one  class  of  plants  can  obtain  the 
nitrogen  necessary  for  their  growth  from  the  air,  as  well 
as  from  the  soil ;  the  other,  as  far  as  we  now  know,  can 
obtain  it  only  from  the  soil.  These  two  groups  of  plants 
are,  therefore,  classified  as  "nitrogen  gatherers"  and 
"  nitrogen  consumers." 


Farmyard  and  Green-Manures  129 

The  nitrogen  gatherers  belong  to  the  legume,  or  clover, 
family,  and  do  not  depend  solely  upon  soil  sources,  but 
rather  gather  the  element  from  outside,  and  thus  do  not 
reduce  the  content  of  soil  nitrogen.  Distinguishing 
features  of  the  plants  of  this  order  are  that  the  seeds  are 
formed  in  a  pod  or  legume,  and  that  they  have  the  power 
of  acquiring  at  least  a  large  part  of  their  nitrogen  from  the 
air.  These,  when  plowed  down  as  green-manures,  add 
directly  to  the  crop-producing  capacity  of  soils  poor  in 
nitrogen,  because  increasing  their  content  of  this  element. 
In  order  that  the  plant  may  obtain  its  nitrogen  from  the 
air,  however,  the  soil  must  originally  contain,  or  must  be 
inoculated  with,  a  specific  germ,  the  presence  of  which  is 
manifested  by  the  growth  of  nodules  upon  the  roots, 
through  which  it  is  believed  the  nitrogen  is  obtained. 
Most  well-tilled  soils  contain  these  germs  in  abundance. 

The  "nitrogen  consumers"  are  those  which  can  obtain 
their  nitrogen  only  from  the  soil ;  these  consume  the  nitro- 
gen existing  there,  and  their  growth  and  removal  exhausts 
the  soil  of  this  element. 

Notwithstanding  the  very  great  advantages  of  the 
"nitrogen  gatherers"  as  green-manures,  they  cannot  be 
solely  depended  upon  to  increase  the  crop-producing 
capacity  of  the  soil.  That  is,  soils  that  are  very  poor, 
both  in  their  content  of  nitrogen  and  of  the  essential 
mineral  elements,  cannot  be  made  very  productive  by  the 
sole  use  of  green-manures.  In  fact,  the  green-manure 
crops  cannot  be  grown  with  advantage  unless  they  are 
supplied  with  an  abundance  of  the  mineral  elements, 
phosphoric  acid  and  potash ;  hence  helpful  green-manuring 
for  such  soils  must  be  preceded  and  accompanied  by  liberal 
fertilization  with  the  minerals,  phosphoric  acid,  potash 
and  lime.  With  these  added  in  sufficient  amounts,  and 


130  Fertilizers 

with  the  specific  bacteria  present  in  the  soil,  their  use 
results  not  only  in  the  addition  of  nitrogen  to  the  soil, 
which  may  be  useful  for  other  plants,  but  by  the  accumu- 
lation of  vegetable  matter,  which  improves  the  physical 
character,  usually  imperfect  in  this  class  of  soils.  The 
nitrogen  thus  introduced  into  the  soil  is  also  in  a  very 
good  form;  that  is,  it  has  a  tendency  to  decay  rapidly 
and  thus  supply  the  needs  of  other  plants,  but  the  helpful 
additions  to  the  soil  are  limited  to  organic  matter  and 
nitrogen.  The  mineral  constituents  absorbed  by  the 
crop  may  be  more  available  for  other  crops,  but  they 
formerly  existed  there.  No  additions  of  these  are  made 
by  the  growing  of  the  crop;  hence  no  system  of  green- 
manuring  can  be  made  successful  unless  there  is  a  previous 
abundance  in  the  soil  of  the  mineral  elements,  or  unless 
these  have  been  directly  applied.  (See  Figs.  8  and  9, 
Plate  V.) 

The  most  useful  crops. 

The  crops  most  useful  for  green-manures  are  red  clover, 
crimson  clover,  alfalfa,  sweet  clover,  winter  vetch,  soy 
beans  and  cowpeas,  because  of  their  capacity  to  gather 
nitrogen,  and  because  of  their  period  and  time  of  growth. 
Whether  these  plants  will  gather  all  of  the  nitrogen  of 
their  growth  from  the  air,  other  conditions  being  good, 
depends  upon  whether  the  soil  is  rich  or  poor  in  nitrogen, 
since  it  has  been  shown  that  these  plants  will  gather  at 
least  a  part  of  the  nitrogen  from  the  soil  in  preference  to 
that  from  the  air,  unless  they  are  starved  in  respect  to  soil 
nitrogen.  The  amounts  that  may  be  gathered  from  the 
air,  therefore,  are  not  measured  by  the  total  content  of 
nitrogen  contained  in  the  plant  grown  (which  may,  in  the 
case  of  good  crops,  amount  to  as  much  as  200  pounds  to 


Farmyard  and  Green-Manures  131 

the  acre,  sufficient  for  the  use  of  several  good  crops  of 
wheat,  or  other  cereal  grains),  but  apparently  by  the 
poverty  of  the  soil  in  this  element.  The  fact  that  an 
accumulation  of  nitrogen  does  occur  has  been  distinctly 
shown,  and  their  continuous  growth,  therefore,  would 
have  a  tendency  to  over-enrich  the  soil  in  this  constituent, 
unless  accompanied  by  an  abundant  supply  of  minerals, 
particularly  in  the  improvement  of  light  lands  and  in 
orchards  and  vineyards,  for  which  their  right  use  is  very 
beneficial. 

Experiments  conducted  in  this  as  well  as  other  coun- 
tries show  that  the  nitrogen  so  gathered  and  stored  in 
the  soil  may  be  readily  obtained  by  cereal  and  other 
nitrogen-consuming  crops.  In  experiments  conducted  by 
the  New  Jersey  Experiment  Station,  on  a  poor,  sandy 
soil,  in  which  the  mineral  elements,  phosphoric  acid, 
potash  and  lime,  only,  were  added,  a  crop  of  cowpeas 
gathered,  in  the  roots  and  tops,  75  pounds  of  nitrogen, 
equivalent  to  that  contained  in  470  pounds  of  nitrate 
of  soda,  which  when  turned  under  was  capable  of  feed- 
ing a  rye  crop  with  sufficient  nitrogen  to  produce  a 
most  excellent  crop,  quite  as  good  as  that  grown  on 
land  long  under  cultivation  and  well  manured.  Further 
experiments  conducted  with  crimson  clover  show  that 
the  nitrogen  gathered  was  capable  of  supplying  the 
needs  of  fruit  trees  quite  as  well  as  when  the  nitrogen 
was  applied  in  the  immediately  available  form  contained 
in  nitrate  of  soda. 

If  it  were  necessary  to  do  so,  numerous  experiments 
might  be  cited  to  show  that  the  nitrogen  is  gathered  from 
the  air  by  these  plants,  and  that  it  is  capable  of  providing 
that  required  for  those  other  crops  which  can  obtain  it 
only  from  the  soil. 


132  Fertilizers 

Green-manure  crops  that  consume  the  nitrogen  in  the  soil. 

In  addition  to  the  legumes,  other  crops  are  used  as  green- 
manures.  Chief  of  these  are  rye,  wheat,  buckwheat, 
mustard,  oats,  barley  and  rape,  not  because  they  are 
capable  of  gathering  nitrogen  directly,  but  because  their 
period  and  time  of  growth  are  such  as  frequently  to 
enable  them  to  serve  a  very  useful  purpose  in  preventing 
losses  in  fertility.  In  the  growth  of  these  crops,  however, 
the  only  real  addition  to  the  soil  is  the  amount  of  non- 
nitrogenous  organic  matter  contained  in  them.  The 
nitrogen  gathered  is  in  direct  proportion  to  the  amount 
contained  in  the  soil  and  the  relative  feeding  capacity  of 
the  plant.  The  nitrogen  is  not  obtained  from  the  atmos- 
phere, and  the  soil  has  not  accumulated  nitrogen  by 
virtue  of  their  growth,  and  is  not  richer  in  this  element, 
except  in  so  far  as  by  their  growth  they  prevent  the 
escape  of  readily  available  nitrogen  into  the  drainage 
waters.  The  nitrogen  gathered  is  "soil  nitrogen,"  and  its 
conversion  into  a  crop  simply  results  in  changing  its  form 
and  place.  The  specific  use  of  these  crops,  therefore,  so 
far  as  directly  contributing  to  the  fertility  of  the  soil  is 
concerned,  is  to  prevent  the  possible  loss  of  nitrogen  and 
other  constituents  by  leaching,  which  is  more  liable  to 
occur  on  uncropped  soils,  though  they  further  contribute 
toward  soil  improvement  by  accumulating  stores  of  non- 
nitrogenous  vegetable  matter. 

These  crops,  also,  in  order  that  they  may  produce  largely, 
must  be  freely  supplied  with  the  mineral  elements,  as  well 
as  with  nitrogen  in  some  form,  and  cannot  be  regarded  as 
a  substitute  for  the  leguminous  crops,  or  as  a  substitute 
for  commercial  fertilizers  in  the  permanent  improvement 
of  the  soil,  in  the  sense  that  they  actually  contribute  to 


Farmyard  and  Green-Manures  133 

its  content  of  fertility  elements,  —  an  opinion  apparently 
held  by  many  who  have  observed  the  good  results  that 
often  follow  their  use.  (See  Fig.  10,  Plate  VI.) 

Mixtures  are  advisable. 

It  is  often  advisable  to  mix  legumes  with  non-legumes 
on  the  principle  that  a  variety  of  seeds  often  make  a 
better  stand.  This  is  particularly  true  when  green- 
manures  are  used  between  cultivated  crops.  The  mixture 
used  must  be  made  up  so  as  to  include  crops  which  grow 
through  the  same  period  of  time,  crops  which  may  be 
expected  to  grow  when  planted  at  the  same  time.  For 
example,  a  mixture  composed  of  sixty  pounds  of  rye, 
twenty  pounds  of  winter  vetch  and  ten  pounds  of  crim- 
son clover  give  most  excellent  results  in  southern  New 
Jersey,  whereas,  conditions  in  northern  New  Jersey  are 
not  suitable  for  crimson  clover. 

Precautions  in  the  use  of  green-manures. 

In  general,  fields  covered  by  green-manure  crops  should 
be  plowed  at  the  customary  time  regardless  of  the  growth 
made  by  the  plants.  Legumes  accumulate  the  greater 
proportion  of  their  nitrogen  supply  in  the  early  stages  of 
growth,  and  it  is  not  wise  to  disturb  the  farm  system  of 
labor.  If  too  great  growth  is  made  by  the  crop,  it  should 
be  mowed  and  harrowed  before  plowing.  In  case  a  heavy 
crop  is  plowed  down,  a  dry  season  may  cause  a  lessening 
of  the  moisture  supply  brought  about  by  the  formation 
of  an  impervious  layer  of  organic  matter  which,  also,  may 
not  decompose  readily,  resulting  in  serious  injury  to  the 
physical  condition  of  the  soil. 

Non-legume  crops  contain,  as  a  rule,  less  nitrogen,  and 
besides,  that  contained  in  them  is  apparently  less  avail- 


134  Fertilizers 

able  than  the  nitrogen  contained  in  the  green-manures 
from  the  leguminous  crops.  In  their  growth,  too,  they 
appropriate  the  immediately  available  nitrogen  of  the  soil, 
and  convert  it  into  the  less  available  organic  form ;  hence 
the  crop  that  follows  is  frequently  unable  to  obtain  its 
food  as  readily  as  would  have  been  the  case,  provided  the 
green-manure  crop  had  not  been  grown,  and  furthermore, 
legumes  may  be  the  cause  of  too  much  nitrogen  in  organic 
form,  frequently  experienced  by  potato  growers.  There- 
fore, while  the  practice  of  using  green-manures  is  a  desir- 
able one  when  properly  understood,  it  should  not  be 
regarded  as  a  means  by  which  soils  may  be  directly  en- 
riched, except  in  the  case  of  the  plants  of  the  legume 
family,  where  nitrogen  is  really  added  to  the  soil.  In  the 
case  of  all  other  crops,  the  benefit  is  indirect,  and  is  in 
proportion  to  the  amount  of  minerals  added. 


CHAPTER  VIII 
LIME  AND  CALCIUM  COMPOUNDS 

THE  foregoing  discussion  has  concerned  almost  entirely 
materials  which  actually  supply  the  plant  with  needed 
food — with  one  or  more  of  the  essential  elements  of  plant- 
food.  Lime,  though  in  a  few  instances  a  food,  is  of  value 
more  particularly  because  its  indirect  action  is  important. 
It  is  not  only  one  of  the  oldest  of  all  manures,  but  it  is, 
also,  the  most  popular  and  continues  to  increase  in  use. 
In  spite  of  these  facts  it  is  still  the  foundation  of  consider- 
able misunderstanding,  probably  because  its  action  is  not 
restricted  to  any  particular  channel.  It  is  known  that 
by  some  plants  it  is  used  as  a  food  and  that  its  greatest 
asset  is  its  mechanical,  chemical  and  biological  activity. 

Lime  is  contained  in  most  soils  in  sufficient  quantities 
for  the  support  of  abundant  plant  growth.  Yet,  there  are 
soils,  particularly  light,  sandy  soils,  to  which  the  addition 
of  lime  directly  promotes  plant  growth.  Permanent 
pastures  of  long  standing  which  were  originally  well 
supplied  with  lime  have  through  years  of  leaching  become 
deficient  in  this  element  in  the  surface  soil,  whereas  the 
same  soil,  had  it  been  thoroughly  cultivated  year  after 
year,  would  contain  sufficient  lime  for  plant  growth  be- 
cause the  cultivation  would  tend  to  counteract  the  down- 
ward movement  of  the  lime  and  hold  a  sufficient  quantity 
in  the  surface  soil. 

135 


136  Fertilizers 

There  is  also  a  number  of  plants  which  require  much 
larger  quantities  of  lime  for  maximum  growth  than  is 
naturally  contained  in  soils.  Of  these  plants  the  legumes, 
especially  alfalfa,  form  the  largest  group. 

OCCURRENCE  OF  LIME 

It  is  fortunate  that  lime  occurs  in  great  abundance. 
Reliable  estimates  show  that  about  one-sixth  of  the  rock 
mass  of  the  earth's  crust  is  composed  of  calcium  com- 
pounds. Vast  tracts  of  country  are  composed  of  nothing 
but  limestone  and  a  large  number  of  the  more  common 
minerals  contain  high  percentages  of  calcium.  Pure  lime 
is  insoluble  in  pure  water  but  is  readily  soluble  in  water 
containing  carbonic  acid,  such  as  rain  water  or  soil  water. 
Such  waters  aid  greatly  in  the  disintegration  of  the  rock 
or  mineral  and  carry  the  lime  to  the  soil. 

In  nature,  lime  exists  chiefly  as  calcium  carbonate  or 
carbonate  of  lime  in  the  forms  of  limestone,  marble  and 
chalk.  It  also  exists  in  combination  with  magnesium 
and  other  chemical  elements.  Oyster  shells  and  clam 
shells  are  composed  almost  entirely  of  calcium  carbonate. 
Gypsum,  a  different  chemical  compound  referred  to  else- 
where, also  occurs  in  nature. 

FORMS  ON  THE  MARKET 

Caustic  lime. 

Limestone  as  it  occurs  in  nature  is  in  the  form  of  a 
hard  rock  and  as  such  it  is  incapable  of  distribution  and 
likewise  incapable  of  exerting  the  many  functions  for 
which  lime  is  used.  Limestone  is  really  a  chemical  com- 
bination of  calcium  oxide  and  carbonic  acid.  When 


Lime  and  Calcium  Compounds  137 

thoroughly  heated,  it  gives  up  the  carbonic  acid,  which 
goes  off  as  a  gas,  leaving  calcium  oxide,  commonly  known 
as  lime,  and  often  termed  "burned  lime,"  "quick-lime," 
"stone-lime"  or  "lump-lime."  In  fact,  100  pounds  of 
pure  limestone  when  properly  burned  gives  up  44  pounds 
of  carbonic  acid,  leaving  56  pounds  of  calcium  oxide. 
This  material  —  calcium  oxide  —  has  become  known  as 
actual  lime  through  the  practice  of  farmers,  manufac- 
turers and  chemists  who  are  accustomed  to  using  it  as  a 
basis  of  comparison  in  estimating  the  quantities  of  lime 
in  the  different  forms.  It  was  the  custom  of  farmers 
located  in  limestone  regions  to  maintain  kilns  and  do  the 
burning  themselves,  but  the  increased  cost  of  wood  and 
high  cost  of  coal  for  burning  and  scarcity  of  labor  have 
made  it  practically  impossible  for  the  farmer  to  compete 
with  the  manufacturer  and  the  home  practice  of  burning 
has  been  abandoned. 

The  resultant  material  after  burning  must  be  slaked 
before  it  is  applied  to  the  soil.  This  is  done  by  adding 
water,  which  is  absorbed  and  the  lime  falls  to  a  fine  powder 
ready  for  distribution.  When  chemically  pure,  burned 
lime  contains  100  per  cent  of  actual  lime  (calcium  oxide), 
but  the  commercial  product  seldom  contains  more  than 
92  per  cent  and  varies  from  78  to  96  per  cent  of  actual 
lime,  depending  upon  the  amount  of  impurities  in  the 
limestone  used  for  burning. 

Ground  limestone. 

By  the  use  of  powerful  grinding  machinery  used  in  the 
manufacture  of  cement,  ground  or  pulverized  limestone 
has  been  put  upon  the  market.  The  rock  limestone  is 
simply  ground,  bagged  and  sold  to  the  farmer.  Chem- 
ically pure  ground  limestone  contains  56  per  cent  of  actual 


138  Fertilizers 

lime,  though  the  commercial  product  seldom  contains 
more  than  52  per  cent  and  varies  from  42  to  54  per  cent 
of  actual  lime. 

The  action  of  this  material  is  dependent  in  large  meas- 
ure upon  the  fineness  of  division.  Products  are  upon  the 
market  which  vary  from  coarse  pieces  to  a  very  find  pow- 
der, 85  per  cent  of  which  will  pass  through  a  200-mesh 
screen.  The  very  coarse  material  acts  very  slowly  and 
should  be  avoided  except  perhaps  for  use  upon  very  light 
soils.  In  general,  75  per  cent  ground  limestone  should 
pass  through  a  100-mesh  screen  for  profitable  agricul- 
tural use. 

Calcium-magnesium  lime. 

What  is  termed  "marble  lime"  is  made  from  pure  lime- 
stone, and  the  burned  lime  thus  obtained  is  practically 
pure  oxide  of  lime.  Limestone,  so  called,  is  not  always 
pure.  Sometimes  it  is  a  mixture  of  lime  and  magnesia, 
in  which  case  it  is  the  mineral  "dolomite"  and  is  termed 
"magnesian  limestone."  A  very  large  quantity  of  the 
lime  used  in  the  eastern  states  is  the  magnesium  form. 
The  burned  lime  from  the  magnesian  limestone  contains 
from  50  to  60  per  cent  of  calcium  oxide,  and  20  per  cent 
or  more  of  magnesium  oxide.  Similar  ground  products 
contain  25  to  30  per  cent  of  calcium  oxide,  and  10  per 
cent  or  more  of  magnesium  oxide.  In  some  instances, 
the  magnesium  oxide  is  of  value,  though  it  is  rather 
inert  in  its  effect,  and  is  less  useful  than  the  lime.  It 
is  believed  to  have  a  beneficial  effect  upon  the  bacterial 
activity  of  soils.  A  safe  method  in  the  purchase  and 
use  of  lime  is  to  adjust  the  price  to  the  proportionate 
percentage  of  actual  lime  present,  practically  in  the  ratio 
of  10  to  7. 


Lime  and  Calcium  Compounds  139 

Ground  burned  lime. 

Ground  burned  lime  is  identical  to  quick-lime,  lump- 
lime  or  burned-lime  except  that  the  manufacturer  grinds 
it  immediately  upon  burning  and  bags  it  to  make  it  ready 
for  shipment.  This  lime  requires  no  slaking  by  the 
farmer  and  its  shipment  in  bags  facilitates  handling  and 
distribution. 

Hydrated  lime. 

Burned  lime  absorbs  water  freely.  When  water  is 
added,  the  resultant  product  is  calcium  hydrate  or 
hydrated  lime.  Burned  lime  is  usually  hydrated  or  slaked 
by  the  farmer  before  application  to  the  soil  is  made,  but 
recently  this  form  of  lime  has  become  a  commercial  prod- 
uct. The  burned  lime  is  ground  and  water  added  in  the 
form  of  steam  which  produces  a  very  finely  divided  prod- 
uct. When  pure  and  thoroughly  hydrated,  this  material 
contains  75.7  per  cent  of  actual  lime,  though  the  commer- 
cial product  varies  from  64  to  72  per  cent  of  actual  lime. 
In  case  the  process  of  hydration  has  been  incomplete,  the 
percentage  of  actual  lime  may  be  much  greater. 

Air-slaked  lime. 

Quick-lime  absorbs  moisture,  and  slakes  when  exposed 
to  the  atmosphere.  Lime  thus  slaked  is  called  "air- 
slaked  lime,"  and  is  usually  less  completely  changed  to  a 
hydrate  than  when  water  is  added.  Quick-lime  also  ab- 
sorbs carbonic  acid  from  the  air,  and  changes  back  to  the 
limestone  form. 

Oyster  shell  lime. 

Oyster  shells  are  nearly  pure  carbonate  of  lime,  and 
oyster  shell  lime,  while  practically  pure  lime,  so  far  as 


140  Fertilizers 

this  element  is  concerned,  is  usually  mixed  with  more  or 
less  dirt  and  other  impurities,  and  is,  therefore,  not  as 
rich  in  lime  as  that  derived  from  pure  limestone.  When 
properly  burned,  it  contains  from  80  to  90  per  cent  of 
actual  lime. 

Ground  oyster  shell  lime  is  an  excellent  source  of  lime, 
containing  from  85  to  95  per  cent  of  calcium  carbonate, 
equivalent  to  48  to  53  per  cent  actual  lime.  This  product 
also  contains  minute  quantities  of  nitrogen  and  phosphoric 
acid.  In  some  cases  as  much  as  seventy-five  cents'  worth 
of  these  elements  is  contained  in  a  ton  of  the  material. 
Ground  oyster  shell  lime  decomposes  very  readily  in  the 
soil,  and  the  fineness  of  division  is  not  such  an  important 
factor  in  determining  its  value  as  it  is  in  the  case  of  ground 
limestone. 

Shell  marl. 

Shell  marl  is  one  of  the  less  important  sources  of  lime. 
There  are  a  number  of  deposits  in  Atlantic  coast  states, 
but  few  of  these  are  worked.  This  product  varies  much  in 
its  content  of  lime  according  to  the  amount  of  impurities 
laid  down  with  it,  though  it  often  contains  as  high  as  95 
per  cent  of  calcium  carbonate,  equivalent  to  53  per  cent 
of  actual  lime.  When  it  may  be  secured  reasonably,  it 
is  one  of  the  best  forms  of  lime,  because  it  is  really  a 
material  which  was  at  one  time  in  solution,  and  hence,  its 
extreme  fineness  of  division  makes  its  action  immediate 
and  complete. 

ACTION  OF  LIME  IN  SOILS 

Lime  has  already  been  referred  to  as  a  plant-food.  Its 
indirect  actions  are  numerous,  producing  many  specific 


PLATE  VI.  —  Wheat  and  Potatoes. 


FIG.    10.  —  WHEAT   GROWN  AS   A   WINTER    COVER-CROP    PRECEDING 
POTATOES,  FREEHOLD,  NEW  JERSEY. 


FIG.  13.  —  MAKING  AN  APPLICATION  OF  ONE  AND  ONE-HALF  TONS  OF 
QUICKLIME  TO  THE  ACRE  FOR  ALFALFA  AFTER  POTATOES. 


Lime  and  Calcium  Compounds  141 

effects  which  are  not  limited  to  any  one  field.  It  affects 
the  soil  itself,  changes  its  texture  and  mechanical  proper- 
ties, such  as  its  power  of  taking  up  and  holding  moisture. 
It  acts  upon  the  supply  of  plant-food  stored  in  the  soil  and 
assists  the  decomposition  of  organic  matter  and  mineral 
substances.  Most  important  of  all  is  the  influence  which 
lime  exerts  upon  the  microorganic  life  of  the  soil,  so  essen- 
tial in  changing  dormant  to  active  forms  of  plant-food. 
Hence,  the  activities  of  lime  in  the  soil  may  be  said  to 
be  threefold, — mechanical,  chemical  and  biological. 

Mechanical  effects  of  lime. 

It  is  often  stated  that  lime  makes  heavy  soils  lighter 
and  light  soils  heavier.  This  is  the  apparent  effect  rather 
than  the  actual.  Applications  of  lime  upon  heavy  soils 
make  them  less  sticky,  more  crumbly,  more  friable,  more 
easily  cultivated,  and  water  passes  through  them  more 
rapidly  as  the  result  of  increased  porosity.  This  condition 
is  brought  about  by  the  flocculation  or  aggregation  of  the 
fine  clay  particles  preventing  shrinkage  in  dry  weather. 

Upon  light  soils  the  reverse  is  true.  An  application  of 
lime  tends  to  increase  the  cohesive  power  of  the  soil, 
resulting  in  a  greater  water-holding  capacity,  as  well  as 
increasing  the  power  to  absorb  moisture  from  below  by 
capillarity.  Light,  sandy  soils  may,  however,  be  injured 
by  large  applications  of  lime,  especially  if  it  is  in  the 
caustic  form  which  causes  a  greater  porosity  and  allows 
water  to  pass  through  too  rapidly.  Upon  muck  or  peat 
soils,  lime  should  always  be  mixed  with  the  surface  soil. 
A  layer  of  lime  spread  over  the  surface  of  such  soils  has  a 
tendency  to  exhaust  the  organic  matter,  and  injury  may 
follow  especially  in  case  of  drouth  because  the  water- 
holding  capacity  is  decreased. 


142  Fertilizers 


Chemical  effects  of  lime. 

Roots  of  peanuts  exude  small  quantities  of  acid  during 
growth,  and  likewise  organic  matter  during  decomposi- 
tion gives  off  acids.  This  is  really  a  provision  of  nature 
because  the  acids  produced  in  this  manner  aid  in  making 
the  soil  stores  of  mineral  plant-food  available,  but  an  ac- 
cumulation of  these  acids  which  is  bound  to  follow  is 
sure  to  give  rise  to  compounds  poisonous  and  harmful  to 
vegetable  life.  Lime  has  long  been  used  to  neutralize 
these  so-called  soil  acids,  and  this  chemical  effect  is  un- 
doubtedly the  best  known  of  all  the  advantages  derived 
from  the  use  of  lime.  To  correct  acidity,  or  sweeten 
sour  soils,  is  a  function  of  lime  thoroughly  appreciated  and 
well  understood.  This  practice  also  kills  many  of  the 
lower  forms  of  plant  life  which  flourish  on  sour  soils  and 
allows  the  more  nutritive  plants  to  grow. 

Lime  supplies  a  necessary  base. 

Soils  that  contain  insufficient  basic  compounds  such  as 
carbonates  of  calcium,  magnesium,  potassium  and  sodium, 
are  not  in  a  condition  to  produce  maximum  crops.  The 
absence  of  such  compounds  permits  the  accumulation  of 
acids.  Under  such  conditions  normal  decomposition  of 
organic  matter,  the  formation  of  nitrate  nitrogen  from 
ammonia,  and  organic  matter,  and  the  utilization  of  at- 
mospheric nitrogen  by  bacterial  activity  are  severely 
hindered.  While  the  correction  of  acidity  and  the  addi- 
tion of  lime  as  a  basic-compound  are  more  or  less  analo- 
gous, it  is  thought  best  to  mention  the  latter  to  point  out 
the  fact  that  the  addition  of  just  enough  lime  to  correct 
acidity  may  not  be  sufficient  to  promote  chemical  and 
bacteriological  functions.  (See  Figs.  11  and  12,  Plate  VII.) 


Lime  and  Calcium  Compounds  143 

Lime  assists  the  decomposition  of  organic  matter. 

Soils  supplied  with  calcium  carbonate  or  other  basic- 
compounds  admit  the  normal  decomposition  of  organic 
matter  which  is  the  foundation  of  the  formation  of  nitrate 
nitrogen  under  conditions  permitting  the  proper  circula- 
tion of  air  and  moisture.  Soils  lacking  calcium  carbonate 
or  other  basic-compounds  permit  the  rapid  accumulation 
of  free  acids  which  poison  the  organisms  responsible  for 
decomposition. 

Lime  makes  soil  potash  available. 

Many  soils  contain  potash  in  large  quantities  in  a  form 
not  usable  by  plants.  Soluble  calcium  compounds  are  of 
prime  importance  in  the  conversion  of  some  of  this  soil 
potash  into  forms  available  for  use  by  plants.  The 
effect  of  soluble  calcium  compounds  in  making  the  in- 
soluble potassium  compounds  of  the  soil  soluble  may  be 
readily  seen  upon  heavy  clay  soils  or  heavy  limestone 
soils  where  good  crops  of  clover  are  produced  annually 
without  the  addition  of  potash  salts.  Though  all  of  the 
conditions  influencing  this  change  are  unknown,  yet  it 
is  safe  to  say  that  it  is  primarily  dependent  upon  the 
nature  of  the  potassium  compounds  existing  in  the  soil. 

Lime  makes  soil  phosphates  available. 

Compounds  containing  phosphorus,  especially  phos- 
phates of  iron  and  aluminum,  occur  in  many  soils.  These 
particular  compounds  are  very  slowly  soluble  in  soil  water. 
The  change  to  a  more  soluble  form  is  brought  about  more 
readily  in  the  presence  of  lime,  especially  when  it  is  in  the 
form  of  carbonate  or  hydrate.  It  was  thought  for  a  long 
time  that  use  of  lime  where  superphosphates  are  used  in 


144  Fertilizers 

abundance  rendered  the  phosphoric  acid  less  efficient  as 
a  plant-food,  but  experiments  have  shown  this  theory  to 
be  greatly  overdrawn. 

Less  plant-food  required. 

Careful  study  of  the  foregoing  paragraphs  shows  clearly 
that  less  plant-food  is  required  where  lime  is  used  in  liberal 
quantity.  In  general,  less  nitrogen,  phosphoric  acid  and 
potash  need  be  added  to  soils  well  supplied  with  lime  and 
in  good  tilth  for  satisfactory  crop  production  than  in  the 
case  of  soils  deficient  in  lime. 

Injurious  chemical  effects. 

Lime  hastens  the  decomposition  of  organic  matter  and 
the  formation  of  nitrates,  as  previously  stated.  If  condi- 
tions are  unfavorable  to  the  formation  of  nitrates,  the 
decomposition  of  organic  matter  may  be  accompanied  by 
a  loss  of  nitrogen  which  escapes  into  the  air  as  a  gas.  In 
case  all  conditions  are  favorable  for  nitrification,  nitrate 
nitrogen  may  be  formed  in  the  soil  more  rapidly  than  the 
plant-life  present  is  capable  of  utilizing  it  and  much  of  it 
would  be  leached  from  the  soil  and  lost  in  the  drainage 
water.  This  is  more  likely  to  occur  in  connection  with 
the  use  of  burned  or  hydrated  lime,  especially  on  light 
soils,  than  with  the  use  of  ground  limestone. 

Effects  of  gypsum. 

Gypsum,  land  plaster  or  calcium  sulfate  previously 
mentioned  should  not  be  confused  with  lime,  though  it  is 
similar  in  the  respect  that  it  carries  the  element  calcium. 
Unlike  lime,  gypsum  will  not  correct  acidity,  and  its  con- 
tinued use  actually  makes  soils  more  acid,  but  it  has  the 
advantage  of  changing  ammonium  carbonate  which  is 


Lime  and  Calcium  Compounds  145 

volatile  into  the  stable  form  of  ammonium  sulfate.  For 
this  reason  it  is  exceptionally  useful  as  a  deoderant  and 
absorbent  in  stables.  It  tends  to  preserve  the  nitrogen  of 
manure  rather  than  to  expel  it  as  do  burned  and  hydrated 
lime. 

BIOLOGICAL  EFFECTS  OF  LIME 

Few  farmers  realize  or  appreciate  the  practical  impor- 
tance of  the  biological  effects  of  lime  which  are  so  im- 
portant in  controlling  the  various  fermentative  actions 
which  go  in  so  abundantly  in  all  soils.  Lime  not  only 
assists  the  decomposition  of  organic  matter  but  it  furnishes 
a  necessary  base  with  which  nitric  acid  combines  in  the 
process  of  nitrification,  and  it  is  most  important  in  the 
formation  of  nitrate  nitrogen.  Lime  creates  conditions 
favorable  for  the  growth  and  development  of  soil  organisms 
which  are  so  important  in  gathering  and  fixing  nitrogen, 
and  at  the  same  time  destroys  many  kinds  of  bacteria  and 
fungi  which  are  the  cause  of  plant-diseases  such  as  "rust," 
"smut "and  "club-root." 

Biological  effects  may  be  harmful. 

Too  great  an  application  of  lime,  causing  a  strongly 
alkaline  soil,  may  prevent  the  normal  process  of  decom- 
position and  nitrification.  Fermentation  of  organic  matter 
goes  on  when  there  is  a  certain  amount  of  alkalinity 
present;  while,  on  the  other  hand,  the  presence  of 
acidity  seems  to  retard  and  check  it.  Too  great  an 
amount  of  alkalinity,  however,  would  retard  fermenta- 
tion as  much  as  too  great  acidity.  This  is  true  more 
particularly  in  case  of  caustic  lime,  but  the  duration  of 
the  injury  ceases  when  it  has  been  changed  to  the 
carbonate  form. 


146  Fertilizers  £ 

There  are  some  plant-diseases,  notably  potato  scab, 
which  thrive  far  better  under  alkaline  soil  conditions,  but 
in  no  case  is  the  disease  caused  by  the  application  of  lime. 
The  bacteria  or  fungi  which  cause  the  disease  must  be 
present  in  .  the  soil  or  subsequently  introduced.  Lime 
merely  creates  conditions  favorable  for  the  spread  and 
development  of  the  disease-causing  organism  and  for  the 
development  of  the  disease. 

It  might  be  added  that  the  character  of  native  vegeta- 
tion is  greatly  influenced  by  the  presence  or  absence  of 
lime  in  soils  just  as  farm  crops  are  influenced.  Chestnut 
trees,  rhododendrons,  arbutus,  blueberry,  huckleberry 
and  many  other  wild  plants  prefer  soils  not  rich  in  lime ; 
while,  on  the  other  hand,  leguminous  crops,  alfalfa,  clovers, 
soy  beans,  cow  peas,  beans,  peas,  wistaria,  locust  trees  and 
the  like,  prefer  soils  exceptionally  well  supplied  with  lime. 
The  common  weed  known  as  sheep  sorrel,  and  many  crops 
including  the  watermelon,  strawberry  and  cranberry, 
thrive  on  soils  distinctly  acid. 

THE  USE   OF  LIME 

A  knowledge  of  the  forms  of  lime  and  the  action  of  lime 
in  a  soil  is  contingent  with  the  efficient  use  of  lime  which 
is  to  a  greater  or  less  extent  an  individual  problem  with 
each  farmer  because  soils,  crops  and  farming  systems 
vary  so  widely,  but  there  are  a  few  fundamental  principles 
which  should  be  thoroughly  understood  by  every  farmer. 
These  principles  involve  a  number  of  questions  the  most 
important  of  which  are:  do  soils  need  lime;  how  much 
lime  should  be  used;  how  and  when  should  it  be 
applied;  and  what  form  of  lime  is  best  suited  to  exist- 
ing conditions? 


Lime  and  Calcium  Compounds  147 


Do  soils  need  lime? 

There  are  a  number  of  ways  to  determine  whether  a 
soil  needs  lime.  It  is  known  that  lime  leaches  out  of  soils, 
that  crop  production  and  decomposition  of  organic  matter 
increase  acidity,  and  therefore  the  application  of  lime 
becomes  necessary  in  the  course  of  time.  For  these  reasons 
the  history  of  any  field  is  an  important  guide.  There  is 
a  common  weed  —  sheep  sorrel  —  which  in  the  absence 
of  cultivation  and  crowding  thrives  in  acid  soils,  and  it  is 
one  of  the  best  natural  indications  of  the  need  of  lime. 
An  attempt  to  raise  red  clover  —  a  crop  decidedly  respon- 
sive to  lime  —  is  a  reliable  method  to  determine  the  char- 
acter of  soil  so  far  as  lime  is  concerned  if  there  is  no  serious 
lack  of  potash  which  may  have  a  similar  effect. 

There  are  a  number  of  chemical  tests  which  are  very 
accurate  but  are  not  entirely  satisfactory  for  the  farmer's 
use.  The  litmus  paper  test  serves  its  purpose  in  the 
laboratory,  but  it  is  not  always  reliable  in  the  field.  It 
is  based  on  the  fact  that  blue  litmus  paper  turns  red 
when  placed  in  contact  with  acid,  and  red  turns  blue 
when  in  contact  with  basic  compounds  such  as  lime. 
Hence  an  acid  soil  will  turn  blue  litmus  red,  and  if  such 
is  the  case,  the  need  of  lime  is  indicated.  When  a 
little  finely  pulverized  soil  fails  to  show  any  visible 
effervescence  when  it  is  covered  with  dilute  hydrochloric 
acid,  it  is  a  good  indication  that  the  proportion  of 
carbonate  of  lime  must  be  below  what  is  desirable  for  the 
healthy  growth  of  vegetation,  but  this  is  not  an  infallible 
rule  nor  a  positive  sign  that  the  soil  contained  excessive 
amounts  of  acid.  Chemical  tests  of  absolute  depend- 
ability may  be  made  in  properly  equipped  laboratories, 
and  it  is  well  for  farmers  to  obtain  such  tests.  But  the 


148  Fertilizers 

indications  at  the  disposal  of  the  farmer  should  be  suf- 
ficient when  good  judgment  is  exercised. 

The  application  of  lime. 

The  character  of  soil,  kind  of  crop  and  character  of 
farming  are  the  most  important  factors  upon  which  the 
use  and  application  of  lime  depend.  In  general,  however, 
it  is  better  to  make  frequent  and  small  applications  than 
large  applications  every  five  or  ten  years.  On  soils  which 
are  poor,  light  and  lacking  in  organic  matter  or  dry,  the 
application  should  be  small,  varying  from  500  to  not  more 
than  1200  pounds  of  actual  lime  or  its  equivalent  to  the 
acre  every  two  or  three  years.  On  heavy  soils  composed 
largely  of  clay  and  well  filled  with  organic  matter,  the 
application  should  be  much  heavier,  from  1200  to  3000 
pounds  of  actual  lime  or  its  equivalent  to  the  acre  every 
two  or  three  years.  Soils  of  this  description  will  make 
better  use  of  larger  quantities,  and  there  is  less  danger  of 
injury  to  soil  or  crop.  If  ground  limestone  is  used,  even 
larger  amounts  may  be  applied. 

There  are  certain  crops  which  respond  greatly  to  lime,, 
others  that  are  negative  and  still  others  that  are  actually 
injured  when  lime  is  present  in  the  soil  in  any  quantity. 
The  farmer  must  study  the  particular  crop  he  is  growing 
and  the  effect  lime  has  upon  its  development  in  order 
that  the  application  of  lime  may  be  properly  adjusted  to 
the  requirements  of  the  crop  as  well  as  to  the  soil. 

When  and  how  to  apply  lime. 

The  tune  of  application  depends  primarily  upon  con- 
venience, but  there  are  a  few  general  rules  which  it  is 
well  to  follow.  Lime  should  be  applied  to  the  surface 


Lime  and  Calcium  Compounds  149 

after  plowing  and  harrowed  in,  because  it  works  down- 
ward and  naturally  leaches  into  the  lower  layers  of  soil. 
For  best  results  it  should  be  applied  at  a  time  when  the 
soil  is  well  filled  with  organic  matter  and  a  crop  should  be 
planted  soon  after  its  application  to  utilize  the  nitrate 
nitrogen  which  is  a  natural  result  of  its  action  upon  the 
organic  matter. 

While  it  is  often  most  convenient  to  apply  lime  in  early 
spring,  on  most  farms,  the  rotation  practiced  or  the  crop 
will  in  many  cases  fix  the  time  of  application ;  for  example, 
previous  to  seeding  clover  or  alfalfa.  In  the  case  of  caustic 
lime,  applications  may  be  made  upon  plowed  ground  in 
fall  without  injury  to  seed.  When  barnyard  manure  or 
fertilizer  containing  nitrogen  in  the  ammonia  or  organic 
form  are  to  be  applied  to  the  same  field  with  caustic  lime, 
the  manure  and  fertilizer  should  be  well  incorporated  with 
the  soil  and  the  lime  applied  after  an  interval  of  two 
weeks  or  more. 

The  form  of  lime  to  use. 

It  is  possible  to  conceive  of  conditions  under  which  a 
specific  form  of  lime  should  be  used  to  the  entire  exclu- 
sion of  other  forms ;  and  yet,  in  general,  the  form  of  lime 
to  use  depends  primarily  upon  the  cost  of  a  pound  of 
actual  lime  or  calcium  oxide,  and  the  quantity  used  should 
be  regulated  by  conditions  of  soil,  kind  of  crop  and  the 
like.  In  other  words,  cost  is  an  important  factor.  The 
farmer  buying  lime  should  first  consider  the  cost  of  actual 
lime  in  the  various  forms  at  his  disposal.  The  cost  of  a 
pound  of  actual  lime  is  easily  calculated  by  multiplying 
the  guaranteed  percentage  of  calcium  oxide  by  twenty 
and  dividing  the  price  of  a  ton  by  it.  The  following  table 
shows  this  calculation  clearly : 


150  Fertilizers 

COMPARATIVE  COST  OP  ACTUAL  LIME  IN  DIFFERENT  FORMS 


1 

a 

Is 

S8 

Si 

fi 

£a 

ii 

o  ® 

KIND  OB  FORM  OF  LIME 

§3 

|s 

C?h  P 

o(2^ 

«^*j 

I    ! 

§8 

gg| 
aoP 

PI 

^    * 

9 

p 

QQ   X 

^  fe 

a  S 

P 
o 

& 

<1° 

0 

a° 

Burned  lump  lime 

90(X20)  = 

1800 

3.50 

3.50 
1800 

$.0019 

Ground  burned  lime  . 

90(X20)  = 

1800 

6.00 

6.00 

Tsoo 

.0033 

Hydrated  lime  .     •    . 

70(X20)  = 

1400 

6.00 

6.00 
1400 

.0042 

Ground  limestone  .     . 

50(X20)  = 

1000 

3.00 

3.00 
1000 

.0030 

At  the  same  time,  the  cost  and  convenience  of  handling 
must  be  considered.  The  user  of  lime  is  not  concerned 
with  the  cost  of  transportation  by  the  railroad  so  long  as  the 
delivered  price  shows  the  cost  of  actual  lime  to  be  reason- 
able. The  cost  of  handling  after  the  lime  arrives  at  the  rail- 
road station  is  the  next  important  consideration.  The  con- 
centration, ease  of  handling,  storage  and  distribution,  and 
the  probable  cost  of  each  operation  are  items  of  practical  sig- 
nificance. In  general,  the  less  concentrated  forms  may  be 
handled  with  greater  ease  and  less  expense,  but  the  cost  of 
cartage  is  practically  doubled  and  it  might  be  better  to  pur- 
chase one  of  the  more  concentrated  forms,  especially  if  the 
farm  is  located  at  considerable  distance  from  the  railroad. 

As  a  factor  of  cost,  fineness  of  division  should  not  be 
overlooked.  Good  burned  lime  showing  a  relatively  high 
percentage  of  actual  lime,  indicating  comparative  free- 
dom from  impurities,  properly  slaked,  is  as  fine  a  powder 
as  it  is  possible  to  obtain  and  there  need  be  no  doubt  of 


Lime  and  Calcium  Compounds  151 

its  immediate  action.  The  fineness  of  ground  limestone 
is  entirely  arbitrary  with  the  manufacturer.  The  finer 
it  is,  the  quicker  and  more  complete  will  be  the  action. 
A  guarantee  of  the  size  of  particles  is  important  and  should 
be  insisted  upon  before  purchase.  Ground  limestone  ca- 
pable of  passing  at  least  75  per  cent  through  a  100-mesh 
screen  or  sieve  gives  prompt  action  and  is  suitable  for  use 
in  most  cases.  A  still  finer  product  is  more  prompt  and 
a  coarser  product  less  prompt  in  action.  If  conditions  are 
such  as  to  warrant  the  use  of  the  coarsely  ground  limestone, 
it  has  the  advantage  of  costing  less. 

Peculiar  conditions  often  exist  or  arise  which  help  to 
determine  the  form  of  lime  to  use  regardless  of  the  fore- 
going suggestions  relating  to  purchase.  Crops  sensitive 
to  alkaline  soil  conditions  are  injured  less  and  thrive  better 
when  the  slower  acting  carbonate  is  used.  This  has 
already  been  referred  to  in  greater  detail.  For  quick- 
growing  crops  requiring  a  soil  rich  in  organic  matter  and 
available  plant-food,  burned  lime  is  preferable  because  it 
brings  about  chemical  changes  of  the  organic  plant-food 
more  quickly,  causing  a  rapid  and  succulent  growth. 
One  point  of  importance  in  this  matter  is  the  solubility 
of  the  different  forms.  The  burned  lime  which  is  changed 
to  the  hydrated  form  by  slaking  is  more  soluble  in  water, 
and  hence  becomes  distributed  throughout  the  soil  more 
readily  than  the  carbonate.  It  is  true  that  slaked  lime 
changes  to  the  carbonate  form,  but  this  change  requires 
some  time  even  under  the  most  favorable  conditions  and 
during  this  period  the  slaked  lime  is  more  active  chemically. 

Distribution  of  lime.      (See  Fig.  13,  Plate  VI.) 

Lime,  no  matter  in  what  form,  should  be  evenly  dis- 
tributed and  when  possible  uniformly  worked  into  the 


152  Fertilizers 

surface  soil.  Burned  lime  should  be  worked  into  the  sur- 
face soil  as  soon  as  practicable  after  application  and  before 
it  has  had  time  to  change  to  the  carbonate  form.  A  uni- 
form distribution  is  not  difficult  when  machinery  is  used. 
Lime  distributers  are  very  efficient  and  make  a  profitable 
investment.  If  no  machinery  is  available  and  the  lime  is 
spread  by  shovel  from  the  back  of  a  wagon,  the  soil  should 
be  worked  very  thoroughly  immediately  after  application. 

Analysis  and  guarantee. 

Nearly  all  states  now  require  guarantees  showing  chemi- 
cal and  mechanical  analyses  of  all  forms  of  lime,  and  the 
farmer  should  be  careful  in  the  purchase  of  lime  to  require 
such  an  analysis  and  guarantee.  Such  an  analysis  should 
show  the  form  of  lime,  the  percentage  of  actual  lime,  the 
percentage  of  magnesia,  the  impurities  and  the  fineness 
of  division  in  the  case  of  carbonate  of  lime. 


CHAPTER  IX 
PURCHASE  OF  FERTILIZERS 

COMMERCIAL  fertilizers,  in  the  form  in  which  they 
are  obtained  by  farmers,  are  made  up  of  varying  pro- 
portions of  one  or  more  products  from  each  class  of 
fertilizing  materials  described.  That  is,  every  manu- 
facturer is  obliged  to  go  to  these  sources  of  supply,  what- 
ever may  be  the  name  given  to  the  finished  product  or 
mixture.  Hence  the  fertilizing  materials  described  are 
not  regarded  as  commercial  fertilizers  in  the  same  light 
as  those  which  they  are  able  to  purchase  under  brand 
names  from  their  local  dealers.  In  the  first  place,  a 
specific  fertilizing  material,  as  distinct  from  a  manufac- 
tured fertilizer,  contains,  as  a  rule,  but  one  of  the  essen- 
tial fertilizing  elements,  and  its  use  under  average  condi- 
tions would  be  far  different  from  one  which  contains  two 
or  all  of  the  essential  fertilizing  elements.  The  materials, 
therefore,  are  classed  as  nitrogenous,  phosphatic  and 
potassic,  according  to  whether  the  material  contains  nitro- 
gen, phosphoric  acid  or  potash  as  its  chief  or  its  only 
constituent  element;  and  these  different  classes,  too, 
may  be  again  subdivided  into  two  distinct  groups,  the 
first  including  "standard,"  or  high-grade  materials, 
and  second,  "general,"  or  low-grade  materials.  This 
classification  is  of  the  utmost  importance. 

153 


154  Fertilizers 


STANDARD  HIGH-GRADE  MATERIALS 

Nitrate  of  soda,  sulfate  of  ammonia  and  dried  blood 
are,  for  example,  standard  or  high-grade  nitrogenous 
materials,  and  belong  to  the  first  group.  They  are  "  stand- 
ard" because  they  do  not  vary  widely  in  their  composi- 
tion. A  definite  quantity  can  be  depended  upon  to  fur- 
nish not  only  practically  the  same  amount  of  the  specific 
constituent,  but  to  furnish  it  in  a  distinct  and  definite 
form,  which  is  identical,  from  whatever  source  derived. 
For  example,  commercial  nitrate  of  soda  does  not  vary 
materially  in  its  composition,  and  the  nitrogen  in  it  is 
always  in  the  form  of  a  nitrate.  The  same  is  true  of  sul- 
fate of  ammonia.  One  ton  will  furnish  practically  as 
much  nitrogen  as  any  other  ton,  and  it  is  always  in  the 
form  of  ammonia.  It  is  also  practically  true  of  high- 
grade  dried  blood.  Each  lot  contains  this  specific  form 
of  organic  nitrogen,  and  will  always  decay  at  practi- 
cally the  same  rate,  if  used  under  the  same  conditions. 
They  are  also  high-grade  products  because  they  are  richer 
in  the  constituent  element,  nitrogen,  than  any  other, 
and  because  this  element  is  immediately  or  quickly  avail- 
able. 

The  South  Carolina,  Florida  and  Tennessee  rock  phos- 
phates differ  from  the  nitrogenous  materials  mentioned, 
inasmuch  as,  in  their  raw  state,  they  are  not  directly 
useful  as  fertilizers,  —  they  are  not  sources  of  available 
phosphoric  acid.  Hence  the  standard  supplies  of  phos- 
phoric acid  are  derived  from  these  materials  after  they 
are  manufactured  into  superphosphates.  The  various 
kinds  of  these  may  be  regarded  as  high-grade  in  the  sense 
that  they  always  possess  a  high  content  of  available  phos- 
phoric acid.  They  are  standard,  too,  not  only  because 


Purchase  of  Fertilizers  155 

of  this,  but  because  they  do  not  vary  widely  in  their  com- 
position. A  definite  amount  from  each  class  can  be 
depended  upon  to  furnish  practically  the  same  amount 
of  available  phosphoric  acid.  For  example,  a  ton  of 
South  Carolina  rock  superphosphate,  from  whatever 
manufacturer  obtained,  will  not  vary  widely  in  its  con- 
tent of  phosphoric  acid,  and  will  always  act  in  the  same 
way  under  similar  conditions.  The  various  German 
potash  salts  are  also  standard  and  high-grade,  since  the 
composition  of  each  grade  and  kind  is  practically  uniform 
in  its  content  of  potash,  which  will  always  act  in  the  same 
way  under  the  same  conditions,  and  since  they  are  richer 
in  the  specific  element,  potash,  than  other  potassic  com- 
pounds suitable  for  the  manufacture  of  fertilizers. 

These  various  standard,  high-grade  products,  when 
used  in  the  manufacture  of  fertilizers,  make  what  are 
called  "chemical  fertilizers/'  because  they  are  really 
crude  chemical  compounds,  and  furnish  the  particular 
fertilizer  elements  in  their  most  concentrated  and  active 
forms. 


FERTILIZING   MATERIALS    WHICH   ARE    VARIABLE    IN    COM- 
POSITION 

The  products  which  are  included  in  the  second  group 
differ  from  the  others,  in  that  they  not  only  vary  in  their 
content  of  the  specific  constituent,  or  in  their  composition, 
but  they  are  also  variable  in  the  sense  that  the  constitu- 
ents contained  in  them  do  not  show  a  uniform  rate  of 
availability.  For  example,  ground  bone  varies  in  its 
composition  owing  to  its  source  and  the  method  of  treat- 
ment, and  the  availability  of  the  constituents,  nitrogen 
and  phosphoric  acid,  also  varies  because  of  these  condi- 


156  Fertilizers 

tions,  and  because  of  its  mechanical  condition  or  degree  of 
fineness.  Different  samples  of  bone  derived  from  the 
same  source,  treated  in  the  same  way,  and  ground  to  the 
same  degree  of  fineness,  would  be  regarded  as  standard,  but 
because  these  conditions  differ,  bone  from  different  sources 
cannot  be  depended  upon  to  act  in  the  same  way  under 
the  identical  climatic  and  soil  conditions.  This  is  also 
true  of  tankage,  which  varies,  not  only  in  the  total  amount 
of  the  constituents  contained  in  it,  but  in  the  proportion 
of  its  two  chief  constituents,  nitrogen  and  phosphoric 
acid,  and  in  the  rate  at  which  they  become  available  to 
plants.  In  this  class  belong,  in  addition  to  the  bone  and 
tankage,  ground  fish,  and  the  various  miscellaneous 
products.  They  cannot  be  depended  upon,  either  in 
respect  to  their  composition  or  their  availability  of  the 
essential  constituents  —  important  advantages  possessed 
by  the  standard  products. 

HIGH-GRADE    AND    LOW-GRADE    FERTILIZERS 

The  fertilizers  manufactured  from  these  two  classes 
of  raw  materials  will  therefore  differ.  Those  made 
from  the  first  class  are  always  high-grade,  both  in  refer- 
ence to  the  quality  and  quantity  of  the  constituents  that 
may  be  contained  in  a  mixture.  Those  manufactured 
from  the  second  group  are  not  high-grade,  so  far  as  the 
form  of  the  constituent  is  concerned,  though  they  may 
be  high-grade  in  the  sense  that  they  contain  large  amounts 
of  them.  In  the  manufacture  of  fertilizers,  too,  as  a  rule, 
all  three  of  the  essential  constituents  are  introduced,  and 
the  buying  of  a  fertilizer  is  really  the  buying  of  the  three 
constituents,  nitrogen,  phosphoric  acid  and  potash. 
Hence,  the  more  concentrated  the  product,  or  the  richer 


Purchase  of  Fertilizers  157 

it  is  in  these  constituents,  the  less  will  be  the  actual  cost 
of  handling  per  unit  of  the  constituents  desired,  and  the 
higher  the  grade  of  the  materials  used,  the  greater  the 
proportionate  activity  of  the  constituents. 

The  "unit"  basis  of  purchase. 

In  commercial  transactions  in  fertilizing  materials, 
two  systems  of  purchase  are  used.  The  first  is  known 
as  the  "unit"  system,  in  which  case  the  quotations,  or 
prices  are  based  on  the  unit.  A  unit  means  one  per 
cent  on  the  basis  of  a  ton,  or  20  pounds.  For  example, 
a  unit  of  available  phosphoric  acid  means  20  pounds,  and 
a  quotation  of  $1  a  unit  would  be  equivalent  to  a  quota- 
tion of  5  cents  a  pound.  In  the  trade,  sales  are  always 
made  on  this  basis.  The  system  is  also  applied  to  such 
nitrogenous  products  as  blood,  meat,  hoof  meal,  concen- 
trated tankage  and  the  like.  The  price  is  fixed  at  so 
much  a  unit  of  ammonia.  This  system  is  probably  the 
most  perfect,  and  certainly  cannot  but  be  satisfactory  to 
both  the  dealer  and  the  consumer.  It  results  in  the 
consumer  receiving  exactly  as  much  as  he  pays  for,  and 
the  producer  is  paid  for  exactly  what  he  delivers.  The 
number  of  units  in  each  material  sold  is  fixed  in  each 
case  by  the  chemist  to  whom  the  samples  are  referred. 

The  "ton"  basis  of  purchase. 

The  other  method  of  purchase  is  known  as  the  "  ton  " 
basis,  and  is  used  almost  exclusively  in  the  sale  of  other 
materials  than  the  standard  products  mentioned,  and 
manufactured  fertilizers.  This  system  works  well  with 
standard  high-grade  products,  since  the  ton  price  is,  in 
this  case,  a  fair  guide  as  to  the  cost  of  the  constituents, 
though  it  cannot  be  as  satisfactory  as  the  other,  since 


158  Fertilizers 

even  the  best  materials  may  vary  sufficiently  to  cause  a 
difference  in  actual  cost  of  the  constituents,  even  though 
the  price  per  ton  remains  unchanged.  In  this  method, 
the  products  are  usually  accompanied  by  a  guarantee, 
the  purpose  of  which  is  to  indicate  the  minimum  amount 
of  the  constituents  contained  in  the  material. 

The  necessity  of  a  guarantee. 

In  the  purchase  of  mixtures,  consumers  should  demand 
that  they  be  accompanied  by  a  guarantee,  because  they 
are  unable  to  determine  the  kind  and  proportion  of  the 
different  materials  entering  into  the  mixture,  either  by 
its  appearance,  weight  or  smell.  In  mixing,  too,  an 
opportunity  is  afforded  for  disguising  poor  forms  of  the 
constituents,  particularly  nitrogen.  That  is,  in  a  mixture 
of  nitrogenous  materials,  potash  salts  and  superphosphates, 
it  would  be  a  difficult  matter  to  determine,  by  mere  phys- 
ical inspection,  the  proportion  of  the  nitrogen  which  had 
been  supplied  in  the  form  of  horn  meal  and  of  blood,  and 
the  statement  of  the  manufacturer  on  this  point  would 
be  valuable  in  proportion  to  his  reliability.  The  fact  that 
in  mixtures  it  is  impossible  for  the  consumer  to  distinguish 
or  determine  the  proportions,  amounts  or  kinds  of  the 
constituents  is  so  fully  recognized  that  it  has  resulted  in 
the  enactment  of  laws  in  most  states,  which  require  that 
manufacturers  or  dealers  in  fertilizers  shall  state  the  actual 
amounts  of  the  different  constituents  contained  in  their 
products,  as  well  as  the  sources  from  which  they  were 
derived,  and  which  fix  a  penalty  for  any  failure  to  comply 
with  the  law  in  this  respect.  A  chemical  control  is  in 
these  cases  provided  for,  and  it  has  been  of  great  service 
both  to  the  good  manufacturers,  because  it  tends  to  reduce 
the  number  of  low-grade  brands  which  would  naturally 


Purchase  of  Fertilizers  159 

come  into  competition  with  them  without  such  protection, 
and  to  the  consumers,  because  it  protects  them  from  frau- 
dulent products. 

Laws  alone  do  not  fully  protect. 

Laws  alone,  however,  are  not  sufficient  to  fully  protect 
the  farmer  in  this  respect.  He  must  possess,  in  addition, 
a  knowledge  of  what  constitutes  a  good  fertilizer,  and 
must  be  able  to  determine  from  the  analysis  whether 
there  is  a  proper  relation  between  the  guarantee  and  the 
selling  price,  and  whether  the  materials  that  have  been 
used  are  of  good  quality.  The  fact  that  there  is  a  very 
decided  lack  of  the  right  sort  of  intelligence  on  this  point, 
is  shown  by  the  results  of  the  work  of  the  different  ferti- 
lizer control  stations.  These  demonstrate  clearly  that 
farmers  do,  in  many  cases,  pay  exorbitant  prices  for  their 
fertilizer  constituents,  not  because  the  manufacturer  did 
not  sell  what  he  claimed  to  sell,  but  because  the  price 
charged  by  the  dealer  was  far  in  excess  of  that  warranted 
by  the  guarantee.  For  example,  it  has  been  repeatedly 
shown  that  of  two  farmers  in  the  same  neighborhood,  the 
one  who  studies  the  matter  and  understands  the  relation 
of  guarantee  to  selling  price,  may  pay  15  cents  a  pound 
for  his  nitrogen,  while  the  other,  who  does  not  study  the 
matter,  buys  on  the  ton  basis,  and  does  not  know  that 
there  should  be  such  a  relation  between  the  two,  may  pay 
30  cents  a  pound  for  the  same  quality  of  the  same  constit- 
uent. This  may  be  illustrated  by  the  following  examples : 

Two  brands  are  offered,  made  up  from  the  same  kind 
and  quality  of  materials.  No.  1  is  guaranteed  to  contain : 

Nitrogen 1% 

Phosphoric  acid  (available) 6% 

Potash 1% 


160  Fertilizers 

and  sells  for  $20  a  ton;  and  No.  2  is  guaranteed  to  con- 
tain: 

Nitrogen 4% 

Phosphoric  acid  (available) 8% 

Potash 2% 

and  sells  for  $22  a  ton.  The  farmer  who  buys  on  the 
ton  basis,  or  is  guided  only  by  the  ton  price,  will  be  in- 
duced to  purchase  the  No.  1  brand,  because  by  so  doing 
he  apparently  saves  $2  a  ton.  The  one  who  studies  the 
relation  of  guarantee  to  selling  price  will  purchase  the 
No.  2  brand,  because  he  finds,  from  a  simple  calculation, 
that  it  furnishes  the  constituents  at  just  one-half  the  cost 
per  pound  of  the  No.  1  brand,  notwithstanding  the  higher 
ton  price,  which  is  shown  by  the  following  calculation : 

No.  1 

Lbs.  Cts. 

to  the  ton   tothelb. 

Nitrogen 1%  X  20  =    20  ®  30  =  $6  00 

Phosphoric  acid  (available)  6%  X  20  =  120  @  10  =  12  00 

Potash 1%  X  20  =    20  @  10  =    200 

$2000 
No.  2 

Lbs.  Cts. 

to  the  ton   to  the  Ib. 

Nitrogen 4%  X  20  =    80  @  15  =  $12  00 

Phosphoric  acid  (available)  8%  X  20  =  160  ®    5  =      8  00 

Potash 2%  X  20  =    40  ©    5  =      200 

$2200 

In  reality,  the  fertilizer  at  $22  a  ton  is  cheaper  than  the 
one  at  $20  a  ton. 

No.  1  No.  8 

Nitrogen $030  $015 

Phosphoric  acid  (available)     .     .          10  05 

Potash 10  05 

This  may  seem  an  extreme  case,  but  it  is  well  within 
the  facts,  which  may  be  ascertained  by  consulting  the 


Purchase  of  Fertilizers 


161 


bulletins  on  fertilizer  analyses,  as  published  by  the  dif- 
ferent states. 

Method  of  statement  of  guarantee  sometimes  misleading. 

Guarantees,  too,  are  sometimes  rendered  confusing 
to  the  purchaser  because  of  the  method  of  their  state- 
ment, though  the  different  methods  used  are,  in  one  sense, 
entirely  legitimate,  because  the  terms  used  are  in  accord- 
ance with  the  facts.  From  a  chemical  standpoint,  at 
any  rate,  it  is  quite  as  legitimate  to  guarantee  the  per- 
centage of  phosphoric  acid  equivalent  to  bone  phosphate 
of  lime,  as  it  is  to  guarantee  the  percentage  of  actual 
phosphoric  acid.  It  is  because  the  consumer  believes 
that  the  "equivalent"  in  combination  means  that  he  is 
obtaining  something  more  than  when  actual  constituents 
only  are  guaranteed,  that  he  is  led  to  purchase  more  freely, 
or  to  pay  a  higher  price.  Nitrogen  may  be  properly 
stated  in  its  equivalent  of  ammonia,  phosphoric  acid 
in  its  equivalent  of  bone  phosphate,  and  potash  in  its 
equivalent  of  muriate  of  potash,  and  it  is  the  business  of 
the  purchaser  to  understand  the  relations  of  the  two 
methods  of  statement,  in  order  that  he  may  not  be  mis- 
led in  his  purchases.  The  following  table  shows  the  terms 
used,  their  equivalents,  and  the  factor  to  use  in  multiply- 
ing, in  order  to  convert  the  one  into  the  other : 

To  convert  the  guarantee  of 

Ammonia  .     . 
Nitrogen    .     . 
Nitrate  of  soda 
Bone  phosphate 
Phosphoric  acid 
Muriate  of  potash 
Actual  potash 
Sulfate  of  potash 
Actual  potash 


?e  of 

Multiply  by 

Nitrogen  .     .    . 

0.8235 

Ammonia  .     .     . 

1.214 

Nitrogen   .     .     . 

0.1647 

into  an 

Phosphoric  acid 

0.458 

equivalent 

Bone  phosphate  . 

2.183 

h 

of 

Actual  potash     . 

0.632 

. 

Muriate  of  potash 

1.583 

Actual  potash     . 

0.54     ' 

. 

Sulfate  of  potash 

1.85 

162  Fertilizers 

Discussion  of  guarantees. 

It  is  shown  in  this  table  that,  in  order  to  convert  am- 
monia into  its  equivalent  of  nitrogen,  the  percentage 
of  ammonia  should  be  multiplied  by  82  per  cent,  or  di- 
vided by  the  factor  1.214,  because  ammonia  is  82  per 
cent  nitrogen,  and  because  one  part  of  the  nitrogen  is 
equivalent  to  1.214  parts  of  ammonia. 

In  order  to  determine  the  cost  of  a  pound  of  ni- 
trogen in  dried  blood,  which  is  quoted.,  for  example, 
at  $3  a  "unit,"  — 20  pounds  of  ammonia, — the  unit 
20  pounds  is  multiplied  by  82  per  cent,  which  gives 
16.40  as  the  pounds  of  nitrogen  offered  for  $3,  or  18.3 
cents  a  pound. 

Bone  phosphate  of  lime  is,  in  round  numbers,  46 
per  cent  actual  phosphoric  acid.  Hence,  by  multiply- 
ing the  bone  phosphate  by  46  per  cent,  the  percent- 
age of  actual  phosphoric  acid  is  obtained.  Ground 
bone,  for  example,  guaranteed  to  contain  from  48  to 
52  per  cent  bone  phosphate,  contains,  in  round  num- 
bers, 22  to  24  per  cent  of  phosphoric  acid.  Sulfate 
of  potash  is  54  per  cent,  and  muriate  of  potash  is  63 
per  cent  "actual"  or  potassium  oxide,  respectively. 
Hence,  to  convert  the  percentages  of  these  forms  into 
their  equivalents  of  "actual,"  they  are  multiplied  by 
the  factors  given. 

In  such  raw  materials  as  nitrate  of  soda,  muriate  of 
potash  and  sulfate  of  potash,  a  method  of  guaranteeing 
is  used  which  is  based  upon  their  purity  as  chemical  salts. 
That  is,  when  pure  they  contain  100  per  cent  of  the  specific 
salt,  and  the  guarantee  accompanying  the  commercial 
product  is  simply  a  statement  indicating  their  purity. 
For  example,  when  nitrate  of  soda  is  guaranteed  to  con- 


Purchase  of  Fertilizers  163 

tain  from  95  to  97  per  cent  pure  nitrate,  it  means  that  it  is 
95  to  97  per  cent  pure,  or  that  3  to  5  per  cent  of  the  sub- 
stance consists  of  impurities;  it  is  not  absolutely  pure 
nitrate  of  soda.  Hence,  the  minimum  percentage  of 
nitrogen  guaranteed  is  15.65  per  cent,  or  95  per  cent  of 
16.47,  the  per  cent  or  pounds  in  each  hundred  of  nitrogen 
contained  in  pure  nitrate  of  soda.  When  muriate  of  potash 
is  guaranteed  80  per  cent  muriate,  it  means  that  80  per 
cent  of  the  salt  consists  of  pure  muriate  of  potash,  and 
because  pure  muriate  of  potash  contains  63  per  cent  of 
actual  potash,  or  potassium  oxide,  the  actual  content  of 
potash  is  derived  by  multiplying  the  63  per  cent,  which 
the  pure  salt  contains,  by  80  per  cent,  and  the  result,  50.5 
per  cent,  represents  the  amount  of  actual  potash  guaran- 
teed. Sulfate  of  potash,  high-grade,  is  usually  guaranteed 
to  be  98  per  cent  pure,  and  since  pure  sulfate  of  potash 
contains  54  per  cent  of  actual  potash,  the  content  of  actual 
potash,  or  potassium  oxide,  guaranteed  is  found  by  mul- 
tiplying the  54  per  cent  by  98  per  cent.  The  following 
illustrations  show  the  two  methods  of  stating  the  guar- 
antees of  raw  materials  and  of  mixed  fertilizers : 

Raw  materials. 

GUARANTEE  ON  BASIS  OP  PURITY 

Nitrate  of  soda     .     .     .  98%,  or  containing  98%  pure  nitrate 

Muriate  of  potash     .     .  80%,  or  containing  80%  pure  muriate 

Sulfate  of  potash       .     .  98%,  or  containing  98%  pure  sulfate 

Kainit    ......  25%,  or  containing  25%  pure  sulfate 

GUARANTEE  ON  BASIS  OF  ACTUAL  CONSTITUENTS 

Nitrate  of  soda,  total  nitrogen 16.00% 

Muriate  of  potash,  actual  potash 50.50% 

Sulfate  of  potash,  actual  potash 53.00% 


164  Fertilizers 

Mixed  fertilizers. 

GUARANTEE  ON  BASIS  OP  EQUIVALENTS  IN  COMBINATION 

Nitrogen  (equivalent  to  ammonia) 3  to  4% 

Available  phosphoric  acid  (equivalent  to  bone  phos- 
phate of  lime) 18  to  22% 

Potash  (equivalent  to  sulfate  of  potash)     .     .     .     .  10  to  12% 

GUARANTEE  ON  BASIS  OF  ACTUAL  CONSTITUENTS 

Nitrogen  (total) 2.50  to    3.25% 

Phosphoric  acid  (available) 8.00  to  10.00% 

Potash  (actual) 5.50  to    6.50% 

The  guarantees  of  the  raw  materials  mean  practically 
the  same  in  the  first  as  in  the  second  case.  In  the  first, 
the  percentages  given  indicate  the  purity  of  the  chemical 
salt;  while  in  the  second,  the  figures  given  indicate  the 
actual  content  of  the  constituent  contained  in  the  chemical 
salt.  In  large  commercial  transactions,  the  sales  are 
frequently  made  on  the  basis  of  certain  purity  percentages ; 
as,  for  example,  muriate  of  potash  is  sold  at  so  much  a 
ton  on  the  basis  of  80  per  cent  muriate.  If  the  analysis 
shows  it  to  contain  less  than  80  per  cent,  then  the  price 
paid  per  ton  is  less  in  proportion  to  such  deficiency. 
If  it  is  shown  to  contain  more  than  80  per  cent,  the  pur- 
chaser pays  for  the  excess  at  the  same  rate.  In  round 
numbers,  a  ton  of  muriate  on  the  80  per  cent  basis  con- 
tains 1000  pounds  of  actual  potash;  if  the  price  is  $40 
a  ton,  the  cost  a  pound  is  4  cents.  If  analysis  shows  but 
900  pounds  instead  of  1000,  the  price  paid  a  ton,  at  4 
cents  a  pound,  is  $36.  If,  on  the  other  hand,  it  is  shown  to 
contain  1110  pounds,  the  price  paid  a  ton  is  $44.  Pur- 
chase made  when  this  method  of  guaranteeing  is  used  is 
practically  equivalent  to  the  "unit"  basis,  though,  as 


Purchase  of  Fertilizers  165 

already  stated,  unless  it  is  thoroughly  understood,  it  is 
likely  to  be  misleading. 

What  has  been  said  of  the  different  statements  of  guar- 
antees of  the  raw  materials,  is  also  true  in  the  case  of  the 
mixed  goods.  In  the  first,  the  percentages  of  the  elements 
that  are  given  represent  the  amounts  when  they  exist 
in  combination  with  other  elements:  nitrogen,  as  am- 
monia ;  phosphoric  acid,  as  bone  phosphate ;  and  potash, 
as  sulfate.  While  in  the  other,  the  percentages  given 
indicate  the  content  of  the  actual  constituents;  namely, 
nitrogen,  phosphoric  acid  and  potash. 

The  advantages  and  disadvantages  of  purchasing  raw  mate- 
rials and  mixed  fertilizers. 

In  the  purchase  of  fertilizers,  therefore,  two  methods 
may  be  adopted :  First,  the  buying  of  fertilizing  materials, 
as  distinct  from  fertilizers,  which  furnish  single  constitu- 
ents like  the  standard  high-grade  products,  or  which  fur- 
nish one  or  two  of  the  constituents,  like  ground  bone,  tank- 
age, fish  and  the  miscellaneous  products ;  these  are  called 
"incomplete,"  because  they  do  not  furnish  all  of  the  three 
essential  constituents.  Second,  the  purchase  of  the  mixed 
manufactured  brands,  which  contain  all  of  the  three  essen- 
tial constituents,  nitrogen,  phosphoric  acid  and  potash, 
which  are  prepared  to  meet  the  demands  of  different  soils 
and  crops,  and  are  called  "complete,"  because  containing 
all  of  the  essential  manurial  constituents,  or  those  liable 
to  be  lacking  in  any  soil.  The  relative  advantage  of  these 
different  methods  of  purchase  depends,  first,  upon  the  cost 
of  the  constituents,  and  second,  upon  the  use  that  is  to  be 
made  of  them. 

It  may  be  urged  that,  on  theoretical  grounds,  there 
are  no  good  reasons  why  nitrate  of  soda,  sulfate  of  am- 


166  Fertilizers 

monia,  dried  blood,  superphosphates  and  potash  com- 
pounds should  be  mixed,  as  the  manufacture  of  these  does 
not  improve  or  change  the  quality  of  the  constituents 
—  it  consists  chiefly  in  simply  grinding,  mixing  and  bag- 
ging. There  are,  however,  advantages  and  disadvantages 
in  both  methods  of  purchase,  the  chief  of  which  are  stated 
below. 

The  advantages  in  the  purchase  and  use  of  raw  materials 
are:1 

1.  A   better   knowledge   of  the   kind   and   quality   of 
plant-food  obtained.     That  is,  these  products  as  a  rule 
possess    characteristics    which    distinguish    them    from 
others  and  from  each  other,  and  they  are  more  likely  to 
be  uniform  in  composition  than  mixtures. 

2.  It  enables  the  use  of  one  or  more  of  the  constituents 
as  may  be  found  necessary,  thus  avoiding  the  expense  of 
purchasing  and  applying  those  not  required  for  the  par- 
ticular crop  or  soil.     The  farmer  is  also  enabled  to  adjust 
the  forms  and  proportions  of  the  various  ingredients  to  suit 
what  he  has  found  to  answer  the  needs  of  his  soil  or  crop. 

3.  A  saving  in  the  cost  of  plant-food,  since  in  their 
concentrated  form,  the  expenses  of  handling,  mixing  and 
rebagging  are  avoided. 

The  chief  disadvantages  are: 

1.  The  materials  are  not  generally  distributed  among 
dealers,  and  thus  not  so  readily  obtained. 

2.  It  is  difficult  to  spread  evenly  and  thinly  products 
of  so  concentrated  a  character,  particularly  the  chemical 
salts,  which,  unless  great  care  is  used,  may  injure  by  com- 
ing in  immediate  contact  with  the  roots  of  plants. 

3.  The  mechanical  condition  or  degree  of  fineness  is 
less  perfect  than  in  the  manufactured  products. 

1 "  First  Principles  of  Agriculture." 


Purchase  of  Fertilizers  167 

The  advantages  in  the  purchase  and  use  of  complete 
manures  are : 

1.  They  are  generally  distributed,  and  can  be  purchased 
in  such  amounts  and  at  such  times  as  are  convenient. 

2.  The  different  materials  may  be  well  proportioned, 
both  as  to  form  of  the  constituents  and  their  relative 
amount  for  the  various  crops. 

3.  The  products  are,  as  a  rule,  finely  ground  and  well 
prepared  for  immediate  use. 

The  chief  disadvantages  are : 

1.  That  it  is  impossible  to  detect  in  a  mixture  whether 
the  materials  are  what  they  are  claimed  to  be. 

2.  That  without  a  true  knowledge  of  what  constitutes 
value,  many  are  led  to  purchase  on  the  ton  basis,  without 
regard  to  the  quantity  and  quality  of  the  plant-food 
offered. 

There  is  no  question  that  the  actual  cost  of  the  con- 
stituent is  less  when  purchased  in  the  fertilizing  material 
than  in  the  manufactured  brand,  as  not  only  the  expenses 
of  mixing  and  bagging  are  saved,  but  the  cost  of  handling 
the  product  per  unit  of  plant-food  is  much  less  in  the  highly 
concentrated  materials  than  in  mixtures  made  up  of  both 
classes  of  fertilizing  materials. 

In  the  purchase  of  fertilizers  by  the  second  method, 
the  cost  of  the  constituents  is  not  only  higher  on  the 
average,  but  the  variations  in  their  cost  are  very  much 
greater,  due  to  the  differences  in  the  charges  made  by  the 
different  manufacturers  for  handling  and  selling  their 
products. 

HOME  MIXTURES 

The  fact  that  fertilizing  materials  are  a  regular  article 
of  trade,  and  may  be  purchased  as  such,  and  the  fact  that 


168  Fertilizers 

a  complete  fertilizer,  so  called,  is  really  only  a  mixture  of 
the  various  manufactured  fertilizing  materials,  has  sug- 
gested the  use  of  what  are  called  "home  mixtures,"  — 
that  is,  their  mixing  by  the  farmer  himself.  This  has 
proved  to  be  very  satisfactory  under  proper  conditions, 
since,  as  already  stated,  the  cost  of  the  constituents  is 
much  less  than  if  secured  in  the  average  manufactured 
brand  (often  from  25  to  50  per  cent),  and  the  mixing  can 
be  performed  by  the  regular  labor  of  the  farm,  and  thus 
not  add  directly  to  the  cost  of  the  constituent. 

This  matter  of  home  mixtures  has  been  carefully 
studied  by  a  number  of  the  experiment  stations,  notably 
Connecticut,  Rhode  Island  and  New  Jersey.  The  re- 
sults of  their  studies  are  published  in  their  regular  reports, 
and  show  that  the  materials  can  be  evenly  mixed  on  the 
farm,  that  the  mechanical  condition  is  good  and  that  the 
results  obtained  from  their  use  are  entirely  satisfactory. 
It  must  be  remembered,  however,  that  whatever  method 
of  purchase  is  used,  the  object  should  be  to  obtain  the  kind 
and  form  of  constituent  best  suited  to  the  conditions  under 
which  they  shall  be  used,  at  the  lowest  price  a  pound. 

In  any  method  of  purchase  which  contemplates  the 
use  of  a  mixture,  care  should  be  taken  in  the  selection  of 
the  brand  or  of  the  formula,  since  in  mixtures  as  well  as 
in  the  raw  materials,  there  are  two  grades,  the  high-grade 
and  the  low-grade  —  high-grade  in  the  sense  that  in 
quality  the  constituents  are  all  good,  and  in  the  sense  that 
maximum  quantities  are  contained;  and  second,  high- 
grade  only  in  that  constituents  of  good  quality  are  fur- 
nished. They  may  be  low-grade  in  the  sense  that  both 
the  quality  and  amount  of  constituents  contained  are 
low,  and  also  in  the  sense  that  only  the  quality  of  the 
constituents  is  low,  the  quantity  being  sufficiently  high. 


Purchase  of  Fertilizers 


169 


Formulas. 

The  following  formulas  are  used  for  the  sole  purpose 
of  illustrating  the  differences  that  may  exist  between 
high-grade  and  low-grade  mixtures,  and  not  as  indicating 
what  should  be  used  to  make  a  good  or  poor  mixture. 

FORMULA  No.  1 
POUNDS 


Amount  Material 

500  Ibs.  nitrate  of 
soda  contains 

1100  Ibs.  acid  phos- 
phate contains 

400  Ibs.  muriate  of 
potash  contains 


Potash 


Price 
100  Lbs. 


Cost 


80     — 


80  costs  $2.50  =  $12.50 


—     180      —    180  costs      .60  =      6.60 


—     —      200  200  costs    2.00  =      8.00 


2000  Ibs.  mixture 
contains 

^20  =  100  Ibs.  mix- 
ture contains 

Guaranteed  com- 
position 


80     180      200  460  and  costs          $27.10 
4.0     9.0     10.0  —    and  costs  1.355 

4.0     9.0     10.0  — 


250  Ibs.  nitrate  of 
soda  contains 

1000  Ibs.  acid  phos- 
phate contains 

80  Ibs.  muriate  of 
potash  contains 

670  Ibs.  make- 
weight or  filler 


FORMULA  No.  2 

40     —       —  40  costs  $2.50  =  $6.25 

—  160      —  160  costs      .60  =  6.00 

—  —       40  40  costs    2.00  =  1.60 


2000  Ibs.  mixture 

contains  40  160  40  240  and  costs 

-^  20  =  100  Ibs. 
mixture  contains  4.0  8.0  2.0  —  and  costs 

Guaranteed  com- 
position 4.0  8.0  2.0  — 


$13.85 
.69 


170 


Fertilizers 


FORMULA  No.  3 

POUNDS 

Ammo-    Phos.  p_j.-0u  Plant- 
nia         Acid    Pota8h    food 


Amount  Material 

600    Ibs.    tankage 

contains  30      90 

400  Ibs.  kainit  contains    —      —      50 

1000     Ibs.      make- 
weight contains 


Price 
100  Lbs. 


120  costs  $1.60 
50  costs      .65 


Cost 

$9.60 
2.60 


30      90      50      170  and  costs 


2000    Ibs.    mixture 

contains 
^    20    =    100   Ibs. 

mixture  contains      1.5     4.5     2.5      8.5  and  costs 
Guaranteed 

composition  1.5     4.5     2.5      — 


$12.20 
.61 


1200   Ibs.    tankage 
contains 

800  Ibs.  kainit  con- 
tains 


FORMULA  No.  4 

60     180      —      240  costs  $1.60  =  $19.20 
—     —       100     100  costs      .65  =      5.20 


2000    Ibs.    mixture 

contains  60  180  100  340  and  costs  $24.40 

-^  20  =  100  Ibs. 

mixture  contains  3.0  9.0  5.0  17.0  and  costs  1.22 

Guaranteed 

composition  3.0     9.0      5.0 


Formula  No.  1  shows  a  high-grade  product,  both  in 
respect  to  quality  of  plant-food  and  concentration,  while 
No.  2  is  high-grade  only  in  respect  to  quality.  In  order 
that  the  plant-food  may  be  distributed  throughout  a  ton 
of  material,  it  is  necessary  to  add  what  is  called  "make- 
weight," or  a  diluent.  These  usually  consist  of  substances 
that  possess  no  direct  fertilizing  value.  High-grade 
mixtures  cannot  be  made  from  low-grade  materials,  and 


Purchase  of  Fertilizers  171 

low-grade  mixtures  cannot  be  made  from  high-grade 
materials  without  adding  "make-weight."  The  advan- 
tages of  high-grade  products  are  concentration  and  high 
quality  of  plant-food. 

It  will  be  observed  that  formula  No.  1  contains  nearly 
twice  as  much  plant-food  as  No.  2,  or,  in  other  words,  it 
will  require  about  two  tons  of  a  fertilizer  made  according 
to  formula  No.  2  to  secure  the  same  total  amount  of  plant- 
food  as  is  contained  in  one  ton  of  No.  1.  Now,  the  mate- 
rial in  No.  2,  other  than  the  actual  plant-food,  is  of  no 
direct  fertilizing  value,  —  it  is  of  no  more  value  as  a  fer- 
tilizer than  the  soil  to  which  it  is  applied,  —  but  the  actual 
cost  of  the  constituents  is  considerably  increased,  because 
the  expenses  of  handling,  bagging  and  shipping  are  just 
double  what  they  would  be  for  No.  1. 

Formula  No.  3  illustrates  a  low-grade  fertilizer  in 
the  sense  that  it  contains  the  poorer  forms  of  the  con- 
stituents, and  furnishes  a  comparatively  small  total 
amount  of  plant-food.  The  nitrogen  is  all  in  the  organic 
form,  and  is  derived  from  tankage,  which,  while  not  the 
poorest,  is  poorer  than  other  forms  of  organic  nitrogen. 
The  phosphoric  acid  is  also  in  organic  combination,  and, 
while  useful  under  many  conditions,  is  less  useful  for  cer- 
tain other  conditions  than  the  soluble  in  Nos.  1  and  2. 
The  potash,  while  soluble,  is  derived  from  kainit,  which, 
because  of  its  large  content  of  chlorin,  is  regarded  as  less 
desirable  for  certain  crops  than  the  more  concentrated 
materials,  muriate,  or  the  high-grade  sulfate,  which  is 
free  from  chlorids.  It  would  require  more  than  2|  tons 
of  a  mixture  made  according  to  this  formula  to  furnish 
as  much  total  plant-food  as  would  be  contained  in  a  mix- 
ture made  according  to  formula  No.  1,  besides  the  dis- 
advantage of  the  lower  quality  of  the  constituents. 


172  Fertilizers 

Formula  No.  4  illustrates  a  mixture  which,  while  rich 
in  total  constituents,  is  not  high-grade  in  its  quality. 

All  of  these  considerations  should  therefore  be  care- 
fully observed  in  the  purchase  of  mixtures,  or  even  in 
the  purchase  of  raw  materials  for  home  mixtures,  and  the 
analysis,  if  properly  made,  will  give  positive  evidence  on 
these  points. 

The  expensiveness  of  low-grade  fertilizers,  as  repre- 
sented by  formulas  Nos.  2  and  3,  is  not  fully  appreciated 
by  the  purchaser  in  all  cases.  He  does  not  stop  to  think 
that  it  is  quite  as  expensive  to  handle  the  material  which 
contains  no  plant-food  as  it  is  to  handle  material  which  is 
rich  in  plant-food. 

The  cost  of  handling  "make-weight." 

A  comparison  of  the  advantages  of  low-grade  and 
high-grade  mixtures  in  this  sense  of  total  quantity  of 
plant-food  may  be  illustrated  as  follows: 

It  has  been  shown  by  continued  studies  at  the  New 
Jersey  Experiment  Station  that  the  charges  of  the  man- 
ufacturers and  dealers  for  mixing,  bagging,  shipping  and 
other  expenses  are,  on  the  average,  $8.50  a  ton ;  and  also 
that  the  average  manufactured  fertilizer  contains  about 
300  pounds  of  actual  fertilizing  constituents  to  a  ton. 
A  careful  study  of  the  fertilizer  trade  indicates  that  these 
conditions  are  also  practically  true  for  other  states  in  which 
large  quantities  of  commercial  fertilizers  are  used. 

A  mixture  of  formula  No.  1  would  contain  460  pounds 
of  actual  available  fertilizing  constituents  in  each  ton 
—  160  pounds,  or  over  50  per  cent  more  than  is  contained 
in  the  average  manufactured  brand.  That  is,  a  farmer 
purchasing  a  brand  similar  to  formula  No.  1  would  secure 
in  2  tons  as  much  plant-food  as  would  be  contained  in 


Purchase  of  Fertilizers  173 

3  tons  of  the  average  manufactured  brand.  Assuming 
that  the  charges  per  pound  of  plant-food  at  the  factory, 
and  the  expense  charges,  are  the  same  in  each  case,  and 
also  that  the  quality  of  plant-food  in  the  one  is  as  good 
as  in  the  other,  the  consumer  would  save  $8.50  by  purchas- 
ing 2  tons  of  the  former  instead  of  3  tons  of  the 
latter.  In  a  few  states  the  consumption  of  fertilizers 
reaches  nearly  100,000  tons  annually,  while  in  many  it 
ranges  from  30,000  to  50,000  tons. 

Thus  is  shown  the  very  great  saving  that  may  be 
effected  in  the  matter  of  the  purchase  of  fertilizers  from 
the  standpoint  of  concentration  alone,  or,  in  other  words, 
the  importance  of  a  definite  knowledge  of  what  constitutes 
value  in  a  fertilizer.  This  saving  may  be  accomplished, 
too,  without  any  detriment  to  the  manufacturer,  since 
the  difference  to  him  between  making  high-grade  or  low- 
grade  goods,  in  reference  to  concentration,  is  largely  a 
matter  of  unskilled  labor.  The  manufacturers  are  in 
the  business  to  cater  to  the  demands  of  the  trade.  If 
consumers  are  intelligent,  high-grade  rather  than  low- 
grade  goods  will  be  provided  by  the  manufacturers. 
Furthermore,  as  already  indicated,  high-grade  in  the 
matter  of  concentration  means  high-grade  in  quality, 
for  high-grade  mixtures  cannot  be  made  from  low-grade 
products. 

GENERAL  ADVICE 

As  farmers  understand  more  fully  the  question  of 
fertilization,  and  as  intensive  methods  of  practice  are 
adopted,  the  tendency  in  the  purchase  of  fertilizers  will 
undoubtedly  be  toward  the  first  method,  or  the  purchase 
of  fertilizing  materials,  rather  than  mixtures,  or  at  any 
rate,  of  high-grade  special  mixtures,  rather  than  what 


174  Fertilizers 

are  now  termed  "standard  brands,"  which  are,  as  a  rule, 
low-grade  in  the  concentrated  sense.  This  tendency 
will  come,  first,  because  intensive  practice  requires  a  larger 
use  of  all  of  the  constituents,  and  second,  a  greater  need 
in  the  growth  of  certain  crops  of  specific  or  dominant 
elements,  and  thus  better  results  are  obtained  from  the 
application  of  single  constituents,  or  the  use  of  special 
formulas,  than  in  "extensive"  practice,  in  which  the  ob- 
ject is  more  to  supplement  the  soil  supplies  than  to  fully 
provide  for  all  the  needs  of  the  plants  for  food. 

The  tendency  toward  cooperative  buying  on  the  part 
of  small  farmers  will  increase  as  it  has  done  in  those  coun- 
tries in  which  there  is  a  larger  use  of  fertilizers  than  here, 
though  the  method  is  already  in  successful  operation  in 
certain  sections  of  the  country,  and  with  very  gratifying 
results.  In  this  method  of  direct  purchase,  the  manu- 
facturer and  the  consumer  are  brought  into  closer  rela- 
tions with  each  other.  Transactions  are  based  upon  the 
transfer  of  a  definite  number  of  pounds  of  a  specific  kind 
and  form  of  plant-food,  rather  than  upon  some  myste- 
riously remarkable  qualities  that  are  claimed,  and  are  by 
many  supposed  to  be  inherent  in  certain  mixtures. 


CHAPTER  X 

CHEMICAL  ANALYSES  OF  FERTILIZERS 

A  COMPLETE  chemical  analysis  of  a  fertilizer  shows 
not  only  the  total  amount  of  the  different  constituents 
contained  in  a  brand,  but  the  form  in  which  they  exist, 
and  in  most  cases,  the  source  of  the  materials  used  is  also 
indicated. 

THE  INTEKPRETATION  OF  AN  ANALYSIS 

An  analysis  may  show  simply  the  total  amount  of 
the  constituents.  This  is  not  a  sufficient  guide  as  to 
the  value  of  a  mixture,  for  while  it  is  not  possible  to 
indicate  absolutely  by  analysis  whether  the  organic 
nitrogen,  for  example,  is  derived  from  blood  (which  is 
one  of  the  best  forms),  or  from  horn  meal  (one  of  the 
poorer  forms),  it  is  possible  to  show  whether  the  nitro- 
gen is  derived  from  nitrate  or  from  ammonia,  whether 
the  phosphoric  acid  is  derived  from  a  superphosphate 
or  a  phosphate,  and  whether  the  potash  present  is  in 
the  form  of  a  sulfate  or  of  a  muriate.  A  high-grade 
or  a  low-grade  fertilizer,  for  example,  may  be  distinctly 
indicated  by  the  analysis,  since  it  is  of  a  high-grade 
if  the  three  forms  of  nitrogen  are  present,  if  the  total 
phosphoric  acid  is  chiefly  soluble  in  water,  and  if  the 
potash  has  been  derived  from  a  sulfate  or  from  a 
muriate.  On  the  other  hand,  if  the  analysis  shows 

175 


176  Fertilizers 

that  the  nitrogen  is  all  in  the  organic  form,  that  only 
a  minimum  percentage  of  the  phosphoric  acid  is  available, 
though  not  soluble,  and  that  a  high  content  of  chlorin 
accompanies  the  potash,  it  is  a  low-grade  product,  in  so 
far  as  the  form  of  the  constituents  is  concerned.  The 
following  statements  of  analyses  of  two  brands,  showing 
the  same  total  content  of  constituents,  illustrate  this 
point : 

ANALYSIS  No.  1 

Nitrogen,  as  nitrate 1  % 

Nitrogen,  as  ammonia 1% 

Nitrogen,  as  organic  matter     ...     1  % 

Total 3% 

Phosphoric  acid,  soluble  ....  8% 
Phosphoric  acid,  reverted  .  .  .  .  1% 
Phosphoric  acid,  insoluble  ....  1  % 

Total  available 9% 

Potash 5% 

Chlorin 0.50% 

ANALYSIS  No.  2 

Nitrogen,  as  nitrate 

Nitrogen,  as  ammonia 

Nitrogen,  as  organic  matter    ...     3% 

Total 3% 

Phosphoric  acid,  soluble      .... 
Phosphoric  acid,  reverted   ....     2% 
Phosphoric  acid,  insoluble  .     ...     8% 

Total  available 2% 

Potash 5% 

Chlorin 10% 

A  study  of  these  two  statements  of  analyses  shows 
that  the  total  contents  of  the  constituents  are  identical, 
3,  10  and  5,  respectively,  in  each  case.  That  is,  so 
far  as  the  total  amounts  are  concerned,  one  brand  fur- 
nishes as  much  as  the  other,  and  from  that  standpoint 


Chemical  Analyses  of  Fertilizers  177 

alone  it  is  as  good  as  the  other ;  but  it  has  been  already 
shown  that  the  value  of  a  fertilizer  depends  not  only  upon 
the  total  content  of  its  constituents,  but  upon  the  form 
in  which  they  exist.  In  the  first  brand  it  is  found  that  two- 
thirds  of  the  total  nitrogen  exists  in  the  soluble  form, 
equally  divided  between  nitrate  and  ammonia;  the  re- 
maining third  is  in  the  organic  form,  and  may  be  derived 
from  blood,  or  from  some  low-grade  materials.  It  is  to  be 
fairly  presumed,  however,  that  when  thus  associated  with 
so  high  a  proportion  of  soluble  nitrogen,  it  is  in  a  good 
form,  as  the  manufacturer  has  given  evidence  of  his  intent 
by  his  liberal  use  of  other  good  forms. 

In  the  case  of  the  phosphoric  acid,  it  is  shown  that 
of  every  100  pounds  of  the  total,  80  pounds  are  soluble, 
10  reverted,  or  nine-tenths  of  the  whole  is  available ;  10 
pounds  of  every  hundred  only  are  insoluble,  which  is  not 
only  an  indication,  but  positive  proof,  that  the  phosphoric 
acid  is  derived  from  a  superphosphate. 

In  the  case  of  potash,  the  chlorin  associated  with  it 
is  but  J  per  cent,  indicating  that  it  has  been  drawn  from 
high-grade  sulfate,  since  kainit  and  muriate  are  rich  in 
chlorin,  while  in  a  high-grade  sulfate  no  appreciable 
amounts  of  chlorin  are  present. 

In  the  second  statement,  all  of  the  nitrogen  is  shown 
to  be  in  the  form  of  organic  matter.  It  may  be  derived 
from  blood,  though  it  is  not  likely  to  have  been  drawn 
from  this  source,  since  of  the  total  phosphoric  acid  but 
20  pounds  to  the  hundred,  or  one-fifth,  is  available,  and 
that  is  reverted  rather  than  soluble,  indicating  that  the 
phosphoric  acid  must  have  been  drawn  from  tankage  or 
from  bone,  or  other  materials  which  contain  reverted  but 
no  soluble  phosphoric  acid,  and  which  also  contain  a  con- 
siderable percentage  of  nitrogen.  The  phosphoric  acid 


178  Fertilizers 

was  certainly  not  drawn  from  a  superphosphate,  or  it 
would  have  shown  a  higher  percentage  of  available,  a  cer- 
tain proportion  of  which  whould  have  been  soluble,  and 
the  percentage  of  insoluble  would  have  been  very  much 
less.  In  the  case  of  potash,  it  is  quite  evident  that  it  was 
drawn  from  kainit,  inasmuch  as  the  percentage  of  chlorin 
exceeds  the  percentage  of  the  potash,  as  would  be  the  case 
if  the  potash  had  been  drawn  from  that  source. 

Thus  it  is  that  a  complete  chemical  analysis  of  a  fer- 
tilizer indicates  very  clearly  the  source  of  the  materials 
by  the  form  in  which  the  constituents  exist  in  the  mixture. 

THE  AGRICULTURAL  VALUE   OF  A  FERTILIZER 

It  is  obvious,  from  what  has  already  been  pointed 
out,  that  the  value  of  a  fertilizer  to  the  farmer  depends 
not  so  much  upon  what  is  paid  for  it  as  upon  the  character 
of  the  materials  used  to  make  it.  This  value  is  termed 
the  "  agricultural  value,"  and  it  is  measured  by  the  value 
of  the  increased  crop  produced  by  its  use.  It  is,  therefore, 
a  variable  factor,  depending  first,  upon  the  availability  of 
its  constituents,  and  second,  upon  the  value  of  the  in- 
creased crop  produced. 

For  example,  in  the  first  place,  the  agricultural  value  of 
a  pound  of  soluble  phosphoric  acid  is  likely  to  be  greater 
than  that  of  a  pound  of  insoluble  when  applied  under  the 
same  conditions  as  to  soil  and  crop,  because  in  the  one  case 
the  element  is  in  its  most  available  form,  while  in  the 
other  it  is  least  available.  In  the  second  place,  the  solu- 
ble phosphoric  acid  may  exert  its  full  effect  and  cause 
a  greatly  increased  yield  on  a  certain  crop,  and  still  not 
cause  an  increase  in  its  value  sufficient  to  pay  the  cost  of 
the  application,  while  for  another  crop  the  same  applica- 


PLATE  VIII.  —  Wheat  and  Timothy. 


FIG.  15.  —  THIRTY-FIVE  BUSHELS  OF  WHEAT  TO  THE  ACRE,  MECHAN- 
ICSBURG,  PENNSYLVANIA. 


FIG.  16.  —  EARLY  SPRING  TOP-DRESSING  WITH  COMMERCIAL  FERTI- 
LIZER HIGH  IN  AVAILABLE  NITROGEN  GREATLY  INCREASES  THE 
YIELD  OF  TIMOTHY. 


Chemical  Analyses  of  Fertilizers  179 

tion  may  result  in  a  very  great  increase  in  the  value  of 
the  crop.  The  character  or  form  of  the  materials  used  in 
a  mixture,  as  well  as  their  suitability  for  the  crop  must, 
therefore,  be  carefully  considered  in  the  purchase  of  fer- 
tilizers. Slow-acting  materials  cannot  be  expected  to  give 
profitable  returns,  particularly  upon  quick-growing  crops, 
nor  expensive  materials  such  profitable  returns,  when  used 
for  crops  of  relatively  low  value,  as  for  crops  of  relatively 
high  value. 

THE  COMMERCIAL  VALUE  OF  A  FERTILIZER 

This  agricultural  value,  however,  is  separate  and 
distinct  from  what  is  termed  "commercial  value/'  or 
cost  in  market.  This  value  is  determined  by  market 
and  trade  conditions,  as  the  cost  of  production  of  the 
crude  materials  and  the  cost  of  their  manufacture  and 
sale.  Since  there  is  no  strict  relation  between  agricul- 
tural and  commercial  or  market  value  of  a  fertilizer  con- 
stituent, it  frequently  happens  that  an  element  in  its 
most  available  form,  and  under  ordinary  conditions  of 
high  agricultural  value,  costs  less  in  market  than  the  same 
element  in  less  available  forms  and  of  a  lower  agricultural 
value.  The  cost  of  production  in  the  one  case  is  lower 
than  in  the  other,  though  the  returns  in  the  field  are  far 
superior. 

It  is  manifestly  impossible  to  fix  an  agricultural  value 
for  any  of  the  constituents  that  will  be  true  under  the 
varying  conditions  of  soil,  crop  and  season,  and  method  of 
use,  though  the  relative  value  of  the  different  forms  under 
uniform  conditions  of  use  may  be  fairly  indicated,  and  the 
analysis  is  the  guide  as  to  their  form.  The  commercial 
value  of  the  different  constituents  in  their  various  forms 


180  Fertilizers 

may,  too,  be  fairly  indicated,  and  will  vary  according  to 
variations  in  trade  conditions.  If  the  wholesale  jobbing 
price  of  nitrogen  as  nitrate  is  15  cents  a  pound,  available 
phosphoric  acid  5  cents  a  pound,  and  potash  4  cents  a 
pound,  these  are  the  prices  which  the  manufacturers  pay. 
Their  increased  cost  in  manufactured  brands,  therefore, 
is  in  proportion  to  the  cost  of  this  work ;  hence  their  cost 
to  the  consumer  at  factory  should  vary  within  reasonably 
narrow  limits,  due  to  variations  in  cost  of  manufacturing 
in  different  localities. 

An  illustration  of  the  commercial  value  is  shown  by 
the  following  example :  Suppose  that  nitrate  of  soda  costs, 
or  can  be  purchased  at  retail,  in  ton  lots,  for  $48  a  ton, 
which  is,  then,  its  commercial  value.  The  commercial 
or  trade  value  of  the  nitrogen  is,  therefore,  15  cents  a 
pound,  since  a  ton  contains  on  the  average  320  pounds 
of  nitrogen.  Or,  suppose  that  the  retail  price  of  avail- 
able phosphoric  acid  in  superphosphates  is  $1  a  unit; 
this  is  its  commercial  value,  and  hence  the  commercial  or 
trade  value  of  the  available  phosphoric  acid  would  be  5 
cents  a  pound,  since  a  unit  contains  20  pounds.  It  does 
not  follow  that  the  application  of  a  pound  of  nitrogen 
costing  15  cents,  and  therefore  having  a  commercial 
value  of  15  cents,  will  result  in  an  increased  crop  worth 
15  cents,  or  that  the  application  of  a  pound  of  phosphoric 
acid  costing  5  cents  a  pound  will  result  in  an  increased 
crop  worth  5  cents.  The  increased  returns  in  crop  from 
their  use  may  be  very  much  greater  or  much  less  than  the 
cost  of  the  constituents,  depending  upon  the  kind  of  crop 
and  the  skill  of  the  user.  In  the  purchase  of  materials, 
however,  a  commercial  valuation  is  a  guide  as  to  the  cost 
of  the  constituents  from  different  manufacturers  or  dealers ; 
and  in  many  states  a  system  of  commercial  values  for 


Chemical  Analyses  of  Fertilizers  181 

mixed  fertilizers  has  been  fixed,  which,  when  properly 
understood,  is  a  useful  method  of  comparison  of  the 
different  brands. 

This  method  is  based  upon  the  fact  that  at  points 
of  supply  a  pound  of  nitrogen,  in  the  form  of  nitrate, 
of  ammonia  or  of  definite  organic  compounds,  or  a 
pound  of  available  phosphoric  acid,  or  of  potash  in  the 
form  of  muriate  or  sulfate,  is  practically  the  same  to  all 
manufacturers.  That  is,  these  cost  prices,  or  trade  values, 
when  applied  to  the  constituents  in  the  mixture,  represent 
their  commercial  value  before  they  are  mixed  to  form 
complete  fertilizers.  Hence,  the  difference  between  the 
valuation  of  a  brand  on  this  basis  and  the  cost  to  the  con- 
sumer represents  the  charges,  including  profit,  for  mixing, 
bagging,  shipping  and  selling  the  goods. 

The  commercial  or  trade  value  for  each  of  these  con- 
stituents is  obtained,  as  already  indicated,  by  simply 
calculating  the  cost,  using  two  factors,  —  the  wholesale 
prices  for  the  different  materials  containing  them,  and 
their  average  composition.  To  this  cost  is  added  a  cer- 
tain percentage,  to  represent  the  cost  of  handling  and  dis- 
tribution in  small  lots.  Thus  the  trade  value  corresponds 
as  nearly  as  may  be  with  the  cost  of  the  constituents  to 
the  farmer.  That  is,  the  price  fixed  represents  what  the 
farmer  would  have  to  pay  the  manufacturer  for  the  con- 
stituents in  the  material  before  it  is  mixed. 

For  example,  suppose  the  wholesale  price  a  ton  of 
nitrate  of  soda  for  the  six  months  preceding  March  1  is 
shown  to  be  $40 ;  the  wholesale  cost  of  nitrogen  in  this 
form  is,  therefore,  12.5  cents  a  pound.  To  this  wholesale 
price  may  be  added  a  certain  sum  to  cover  the  expenses 
of  handling,  usually  20  per  cent,  thus  making  the  retail 
price  a  ton  $48,  and  the  trade  or  commercial  value  of  the 


182  Fertilizers 

nitrogen  15  cents  a  pound.  That  is,  the  $48  a  ton,  or  15 
cents  a  pound,  represents  the  retail  cost  a  pound  of  nitrate 
nitrogen.  This,  if  applied  to  the  nitrogen  as  nitrate,  in 
the  mixed  fertilizer,  will  show  what  it  could  have  been 
bought  for  as  nitrate  in  the  unmixed  fertilizer.  The 
values  for  the  other  constituents  are  derived  in  the  same 
way.  These,  together,  make  the  schedule  of  trade  or  com- 
mercial values  of  the  constituents  which  are  used  in  the 
computing  of  the  commercial  values  of  mixed  fertilizers. 
The  schedule  of  values  is  revised  annually,  and,  as  nearly 
as  possible,  at  the  same  time  in  the  year.  The  following 
schedule,  used  as  an  illustration  of  this  point,  was  adopted 
by  the  Directors  and  Chemists  of  the  Experiment  Stations 
of  New  Jersey  and  the  New  England  states  for  use  in  that 
territory  for  the  year  1914 : 

SCHEDULE  OP  TRADE  VALUES  Cents 

per  pound 

Nitrogen  in  nitrates 16.5 

Nitrogen  in  ammonia  salts 16.5 

Organic  nitrogen  in  fine *  ground  fish,  meat  and  blood  .  22.5 

Organic  nitrogen  in  cotton-seed  meal  and  castor  pomace  22.5 

Organic  nitrogen  in  fine  x  bone  and  tankage 21.5 

Organic  nitrogen  in  mixed  fertilizers 19.5 

Organic  nitrogen  in  coarse  1  bone  and  tankage  ....  17.5 

Phosphoric  acid,  soluble  in  water 4.5 

Phosphoric  acid,  soluble  in  ammonium  citrate  ....  4.0 

Phosphoric  acid  in  fine  x  bone  and  tankage 4.0 

Phosphoric  acid  in  cotton-seed  meal  and  castor  pomace  4.0 

Phosphoric  acid  in  coarse  1  bone,  tankage  and  ashes  .  .  3.5 
Phosphoric  acid,  insoluble  in  water  and  in  ammonium 

citrate 2.0 

Potash  in  high-grade  sulf ate,  and  in  the  forms  free  from 

muriate  (chlorids) 5.0 

Potash  in  muriate 4.0 

Potash  in  cotton-seed  meal  and  castor  pomace  ...  5.0 

1  "Fine"  signifies  such  as  will  pass  through  a  sieve  with 
circular  holes  ds  of  an  inch  in  diameter,  and  "coarse"  such  as 
will  not. 


Chemical  Analyses  of  Fertilizers  183 

It  will  be  observed  that  the  schedule  gives  the  cost 
a  pound  of  the  different  forms  of  nitrogen,  and  of  high- 
grade  organic  nitrogenous  materials;  of  nitrogen  and 
phosphoric  acid  in  ground  bone  and  tankage ;  of  available 
phosphoric  acid  in  superphosphates,  and  of  actual  potash 
in  the  potash  salts,  and  is  a  useful  guide  also  in  showing 
that  the  nitrogen,  phosphoric  acid  and  potash  contained 
in  these  materials  can  be  purchased  in  ton  lots  for  the  prices 
mentioned.  The  valuations  of  mixed  fertilizers,  obtained 
by  the  use  of  this  schedule,  are  entirely  commercial ;  they 
are  not  intended  to  indicate  even  a  possible  agricultural  value. 
This  point  needs  to  be  emphasized,  as  many  are  inclined 
to  interpret  them  as  not  only  guides  as  to  agricultural 
value,  but  as  positive  statements  of  such  value.  It  can 
be  said,  however,  that  those  who  do  so  do  not  familiarize 
themselves  with  the  discussions  that  usually  accompany 
reports  of  analyses.  The  different  trade  values  given  for 
the  nitrogen  and  phosphoric  acid  in  the  two  grades  of  bone 
represent  their  value  in  the  form  of  ground  bone  and  of 
bone  meal,  products  which  are  distinctly  recognized  in 
the  market,  and  which  are  quoted  at  different  prices. 
The  coarser  ground  bone  is  lower  in  price  than  the  finer 
bone  meal. 

The  accuracy  of  the  schedule  of  values  can  be  shown 
by  comparing  it  with  the  actual  prices  paid  for  the  con- 
stituents in  the  different  materials,  and  such  comparisons 
as  have  been  made  from  year  to  year,  by  a  number  of  the 
institutions  exercising  an  analysis  control,  show  that 
manufacturers  and  dealers  are  willing  to  sell  to  farmers 
at  prices  corresponding  very  closely  with  the  schedule.1 

A  value  is  placed  upon  the  insoluble  phosphoric  acid 

1  See  Bulletins  Connecticut  and  New  Jersey  Experiment 
Stations. 


184  Fertilizers 

in  mixed  fertilizers,  not  because  all  insoluble  costs  the 
price  given,  but  because  in  mixtures  it  is  assumed  that  the 
phosphoric  acid  is  drawn  from  organic  sources,  which  do 
cost,  at  least,  the  price  given. 

There  are  arguments  both  in  favor  of  and  in  oppo- 
sition to  this  method  of  comparing  the  commercial  values 
of  mixed  fertilizers.  The  chief  arguments  in  opposition 
may  be  stated  as  follows : 

First,  that  the  prices  of  these  materials  vary,  and 
hence  in  order  to  represent  the  actual  commercial  value 
at  the  time  the  sales  are  made,  they  should  be  changed 
as  the  markets  change. 

Second,  the  valuations  are  misleading,  because  the 
farmer  does  not  clearly  understand  their  meaning,  and 
is  thus  guided  in  his  judgment  of  the  usefulness  or  agri- 
cultural value  of  a  fertilizer  by  the  stated  commercial 
value,  as  shown  by  this  method,  rather  than  by  the  kind, 
form  and  proportion  of  constituents  that  may  be  contained 
in  it,  and  upon  which  its  agricultural  value  should  be 
based. 

Third,  the  chemical  analysis  does  not  show  absolutely 
the  sources  of  the  materials,  and  thus  it  is  difficult  to  place 
a  true  commercial  value  upon  a  mixture.  This  is  espe- 
cially true  of  organic  nitrogen,  since  because  it  is  impos- 
sible to  separate  the  amounts  that  may  be  derived  from 
different  materials,  a  uniform  value  is  placed  upon  the 
total  nitrogen  found,  whether  it  is  derived  from  the  best 
forms,  as  dried  blood  and  dried  meat,  or  whether  derived 
from  horn  meal,  ground  leather  or  other  low-grade  forms 
of  nitrogenous  material.  This  encourages  the  use  of  low- 
grade  products  by  unscrupulous  manufacturers,  to  the  real 
detriment  of  the  trade  as  a  whole. 

Fourth,  that  the  commercial  value  so  fixed  militates 


Chemical  Analyses  of  Fertilizers  185 

against  the  use  of  certain  kinds  of  good  materials,  and 
in  favor  of  certain  kinds  of  poorer  materials.  That  is, 
a  valuation  of  2  cents  a  pound  for  insoluble  phosphoric 
acid  in  complete  fertilizers,  for  example,  is  a  direct  encour- 
agement to  include  in  the  mixture  a  considerable  propor- 
tion of  the  insoluble  phosphoric  acid  from  South  Carolina, 
and  other  rock  phosphates,  the  value  of  which  is  ignored 
in  commercial  transactions;  while  that  price  (2  cents) 
does  not  give  a  fair  value  to  the  phosphoric  acid  contained 
in  bone,  tankage  and  natural  guanos,  products  in  which 
the  commercial  value  of  the  insoluble  is  recognized,  — 
that  is,  mixtures  which  contain  bone  and  tankage,  and 
which  furnish  phosphoric  acid  largely  in  an  insoluble  form. 
The  valuation  fixed  for  this  form  is  too  low  to  fully  repre- 
sent the  commercial  value  of  these  goods.  It  is  also  said 
that  the  trade  value  for  available  phosphoric  acid  in  the 
mixtures  encourages  the  use  of  superphosphates  from  the 
rock  phosphates,  and  discourages  the  use  of  superphos- 
phates from  bone-black,  bone-ash  and  dissolved  bone, 
because  the  trade  or  commercial  values  represent  the 
average  cost  of  available  phosphoric  acid  in  the  super- 
phosphates from  all  of  these,  while  the  latter  materials, 
because  of  actual  commercial  conditions,  cost  more  than 
the  superphosphates  from  the  former. 

The  chief  arguments  in  favor  are : 

First,  that  it  is  not  asserted  that  the  system  shows  abso- 
lutely the  commercial  value  of  each  brand  at  the  time  the 
sales  are  made,  but  the  comparative  commercial  value. 

Second.  They  are  not  misleading.  The  commercial 
valuations  are  not  intended  to  be  a  guide  as  to  the  agri- 
cultural value  of  a  fertilizer.  It  is  distinctly  stated  in  the 
reports  of  analyses  that  the  comparative  values  are 
purely  commercial. 


186  Fertilizers 

Third.  It  is  a  system  which  more  nearly  approaches 
perfection  than  any  other  that  has  been  devised,  is  edu- 
cative in  its  tendency,  and  is  a  safe  guide,  in  the  majority 
of  instances,  as  to  the  charges  made  for  mixing,  handling 
and  selling  plant-food  contained  in  the  different  brands. 
If  the  analysis  is  properly  interpreted,  as  already  indicated, 
it  is  the  purchaser's  fault  if  he  buys  poor  forms  of  plant- 
food  at  a  high  price.  It  is  certainly  a  safer  guide  than 
mere  name  of  brand,  and  does  not  encourage  the  use  of 
poor  materials. 

Fourth.  Any  system  of  comparison  of  brands  must 
leave  a  great  deal  to  the  judgment  of  the  purchaser. 
He  must  interpret  for  himself  whether  he  would  rather 
that  his  phosphoric  acid  were  derived  from  one  source 
or  another,  whether  he  would  prefer  to  pay  a  higher 
price  for  insoluble  phosphoric  acid  in  acid  phosphate, 
and  have  the  remainder  soluble,  than  to  pay  the  same 
or  a  greater  price  for  the  insoluble  phosphoric  acid  in 
bone,  and  have  the  remainder  of  it  in  the  reverted  form. 
These  conditions  are  again  indicated  by  the  analysis  which 
accompanies  the  valuation ;  the  valuations  are,  therefore, 
not  to  be  used  in  total  disregard  of  the  composition.  If 
they  are  so  used,  it  is  not  the  fault  of  the  system.  That 
it  militates  against  the  use  of  high-priced  superphos- 
phates, if  they  are  no  better  than  the  lower-priced  ones, 
is  no  argument  against  the  system,  but  rather  for  it,  since 
it  tends  toward  a  readjustment  of  the  prices,  a  condition 
that  must  be  met  in  all  competitive  trades.  Furthermore, 
the  valuation  system  has  been  effective  in  driving  out  ma- 
terials that  are  either  fraudulent  in  their  character  or  of 
very  low-grade.  It  is  impossible  to  obtain  a  high  valua- 
tion on  poor  materials,  and  in  the  majority  of  cases  de- 
pendence upon  valuations  alone  would  be  a  safe  guide 


Chemical  Analyses  of  Fertilizers  187 

as  to  the  comparative  agricultural  value  of  brands  of 
the  same  general  composition. 

CALCULATION  OF  COMMERCIAL  VALUES 

The  following  examples  illustrate  how  commercial 
values  of  complete  fertilizers  and  of  ground  bone  are 
calculated.  The  mixed,  or  complete,  fertilizer  contains 
the  three  forms  of  nitrogen,  three  of  phosphoric  acid, 
and  the  two  forms  of  potash.  In  the  bone,  it  is  assumed 
that  50  per  cent  of  the  meal  is  finer  than  1-50  inch,  and  is, 
therefore,  regarded  as  fine,  and  that  50  per  cent  is  coarser 
than  1-50  inch,  and  is,  therefore,  regarded  as  coarse; 
and  it  is  also  assumed  that  the  proportions  of  the  nitrogen 
and  phosphoric  acid  in  the  fine  and  coarse  is  the  same; 
also,  that  the  analysis  shows  the  bone  to  contain  4  per 
cent  of  nitrogen  and  20  per  cent  of  phosphoric  acid : 

A  COMPLETE  FERTILIZER 

1  234 

Estimated 
Value     value  per 

%  or  Iba.  Lbs.       per  Ib.    ton  of  each 

per  100  pear  ton       eta.     constituent 

Nitrogen,  as  nitrates    ...          1  X  20  =    20  X  16.5  =  $3.30 


Nitrogen,  as  ammonia  salts 
Nitrogen,  as  organic  matter 
Phosphoric  acid,  soluble 
Phosphoric  acid,  reverted 
Phosphoric  acid,  insoluble 
Potash,  as  muriate       .     . 
Potash,  as  sulphate      .     . 


1  X  20  =    20  X  16.5  =  3.30 

1  X  20  =    20  X  19.5  =  3.90 

8  X  20  =  160  X    4.5  =  7.20 

1  X  20  =    20  X    4.0  =  .80 

1  X  20  =    20  X    2.0  =  .40 

5  X  20  =  100  X    4.0  =  4.00 

5  X  20  =  100  X    5.0  =  5.00 


Total  estimated  value  per  ton $26.90 

The  first  column  shows  the  percentage  of  the  con- 
stituents contained,  which,  multiplied  by  20,  gives  the 
pounds  per  ton  in  the  second  column,  which,  multiplied 


188  Fertilizers 

by  the  schedule  prices  a  pound,  gives  the  valuation  per 
ton,  as  shown  in  the  fourth  column. 

GROUND  BONE 
12  3  456 

%  or  Ibs.  %  of  Value  Estimated 

per      fine-  %  or  Ibs.  Lbs.     per  lb.     value 

00      ness  per  100  per  ton      cts.       per  ton 

4X50=    2  in  fine       X20=    40X  21.5  =  $8.60 
4  X  50  =    2  in  coarse  X  20  =    40  X  17.5  =    7.00 


Nitrogen 
Phosphoric 


20X50=  10  in  fine       X20  =  200X    4.0=    8.00 
acid    .     .        20  X  50  =  10  in  coarse  X  20  =  200  X    3.5  =    7.00 
Total  estimated  value  a  ton $30.60 

The  first  column  of  figures  shows  the  per  cent,  or 
pounds  per  hundred,  of  the  constituents,  which  is  mul- 
tiplied by  the  percentage  of  fineness,  which  gives  the 
percentage  or  pounds  to  the  hundred  of  fine  or  coarse 
in  the  third  column.  The  calculation  is  then  finished  as 
in  the  case  of  complete  fertilizers. 

THE  UNIFORMITY  OF  MANUFACTURED  BRANDS 

Another  point  which  consumers  of  fertilizers  are  in- 
terested in  is  the  reliability  of  the  various  brands.  That 
is,  they  desire  to  know  whether  a  brand  that  shows  good 
forms  of  nitrogen,  of  phosphoric  acid,  and  of  potash  in 
one  year  may  be  depended  upon  to  furnish  approximately 
the  same  the  following  year,  or  whether  the  manufacturers 
change  their  formulas  from  year  to  year  to  conform  to  the 
relative  cost  of  the  different  materials;  that  is,  whether 
when  nitrogen  is  relatively  expensive  and  phosphoric 
acid  is  relatively  cheap,  they  introduce  a  larger  proportion 
of  phosphoric  acid  and  a  smaller  percentage  of  nitrogen ; 
whether  when  organic  nitrogen  is  cheap  and  nitrate  and 


Chemical  Analyses  of  Fertilizers  189 

ammonia  nitrogen  are  dear,  they  change  the  proportions 
of  these  to  correspond  with  the  difference  in  price,  in  order 
to  retain  the  same  selling  price. 

This  is  an  important  point,  since  after  a  certain  brand 
has  been  shown  to  be  better  suited  than  another  to  their 
conditions  of  soil,  to  change  the  formula,  both  in  refer- 
ence to  the  character  and  proportions,  may  mean  to  the 
purchaser  the  difference  between  profit  and  loss. 

Evidence  on  this  point  can  be  obtained  from  the  re- 
ports showing  the  results  of  the  analyses  of  the  different 
brands  from  year  to  year,  and  a  careful  study  of  these 
shows  that  genuine  manufacturers  of  fertilizers  —  those 
who  make  it  their  sole  business,  rather  than  a  side  issue 
or  an  adjunct  to  another  business  —  can  be  fully  de- 
pended upon  in  this  respect.  They  know  that  the  farmer's 
interest  is  their  interest,  and  that  their  sales  will  depend, 
other  things  being  equal,  upon  the  increased  crop  results 
that  the  farmer  secures ;  that  the  permanency  and  success 
of  their  business  will  depend  upon  the  successful  and 
profitable  use  of  their  product ;  and  that  they  cannot  af- 
ford to  and  do  not  change  their  formulas  from  year  to  year, 
either  in  proportion  or  quality  of  constituents,  to  cor- 
respond with  the  changes  in  price  of  the  materials.  Their 
brands  can  be  depended  upon  to  furnish  practically  the 
same  amount,  kind  and  proportion  of  plant-food  from 
year  to  year. 

The  value  of  a  fertilizer  depends  upon  the  kind,  quality 
and  form  of  plant-food,  as  shown  by  the  analysis.  Value 
does  not  depend  upon  who  the  manufacturer  is,  or  what 
the  statements  may  be  concerning  the  usefulness  of  special 
manipulation,  nor  to  any  great  extent  upon  special  formu- 
las, unless  the  farmer  has  positive  knowledge  of  the  char- 
acter of  his  own  conditions.  Formulas  derived  both  in 


190  Fertilizers 

kind  and  proportion  from  the  same  materials  will  do 
equally  well  under  the  same  conditions.  So  far  as  the 
matter  has  been  investigated,  there  is  no  specific  virtue 
added  by  what  is  claimed  to  be  the  "blending"  of  the 
materials. 

In  the  whole  matter  of  the  purchase  of  fertilizers,  no 
guide,  however  good,  can  take  the  place  of  intelligence  on 
the  part  of  the  purchaser.  This  intelligence  must  be 
exercised  in  the  selection  of  forms  of  plant-food,  in  the 
preparation  of  formulas,  in  the  interpretation  of  guar- 
antees and  of  commercial  values,  and  in  the  method  of 
using  the  fertilizer. 


CHAPTER  XI 
METHODS  OF  USE  OF  FERTILIZERS 

THE  primary  object  in  the  use  of  a  commercial  fertilizer 
is  to  receive  a  profit  from  the  increase  in  the  yield  of  crops 
from  the  land  to  which  it  is  applied;  and  this  may  be 
derived  either  from  the  immediate  crop,  or  from  the  larger 
yield  of  a  number  of  crops.  That  the  greatest  immediate 
or  prospective  profit  may  be  gained,  a  wide  knowledge  of 
conditions  which  have  either  a  direct  or  indirect  bearing 
upon  the  result  is  essential. 

CONDITIONS   WHICH   MODIFY   THE    USEFULNESS   OF 
FERTILIZERS 

In  fact,  the  controlling  conditions  surrounding  the 
matter  are  so  numerous  and  so  various  that  it  is  impossible, 
with  our  present  knowledge,  to  lay  down  positive  rules  for 
our  guidance.  At  best,  only  suggestions  can  be  offered. 

We  may  possess  a  full  knowledge  of  both  the  kind  and 
form  of  existing  fertilizer  supplies,  their  cost  and  the  action 
under  known  conditions  of  the  constituents  contained  in 
each,  as  well  as  their  maximum  capability  for  increasing 
the  crop,  but  together  with  this  knowledge,  it  is  essential 
that  we  should  know  how  these  facts  and  principles  must 
be  applied  to  each  individual  crop,  soil  and  condition,  and 
yet  even  with  this,  absolute  certainty  of  profit  is  not 
guaranteed.  A  few  of  the  more  important  conditions 

191 


192  Fertilizers 

which  control  the  profitable  use  of  fertilizers  are,  therefore, 
briefly  discussed,  in  order  to  arrive  at  a  better  under- 
standing of  the  practical  suggestions  and  concrete  examples 
given  in  subsequent  chapters. 

Derivation  of  soil  a  guide  as  to  its  possible  deficiencies. 

The  first  consideration  is  the  soil  itself,  and  its  influence. 
It  is  well  known  that  a  wide  difference  exists  in  soils,  both 
in  reference  to  their  chemical  character  or  composition, 
and  to  their  physical  properties,  each  having  a  direct 
influence  in  determining  the  effect  of  any  specific  applica- 
tion of  fertilizers.  These  differences  in  soils  are  due  to 
changes  which  were  wrought  in  the  surface  of  the  earth 
during  its  formation,  and  which  are  continuing  in  a  small 
way  at  the  present  time.  It  is  believed  that  the  original 
earth  crust  contained  all  the  minerals  now  found  in  it,  but 
that  in  the  beginning  they  were  distributed  more  uniformly 
throughout  its  mass,  and  that  the  soils  as  they  exist  at  the 
present  time,  and  as  a  result  of  the  direct  disintegration  of 
the  original  rock,  represent  a  very  small  area  of  the  earth's 
surface.  They  are  not  now  constant,  but  variable  in  their 
character.  The  various  changes  that  have  taken  place 
during  geologic  time  have  resulted  in  the  breaking  up  of 
the  original  rocks,  a  part  having  been  separated  mechani- 
cally and  being  represented  by  various  sizes  of  particles, 
and  a  part  rendered  soluble.  The  fragments  and  the 
soluble  portions  thus  separated  have  not  been  deposited 
again  in  the  same  proportions  as  they  existed  in  the  original 
rock,  which  has  caused  a  very  wide  variation  in  the  chemi- 
cal composition  of  the  different  soil  deposits.  The  process 
and  its  results  may  be  shown  at  the  present  time  in  the 
wearing  away  of  rocks.  The  harder,  sandy  particles  sep- 
arate mechanically,  and  because  of  the  difference  in  the 


Methods  of  Use  of  Fertilizers  193 

size  of  the  particles,  the  coarser  are  deposited  as  gravel  or 
sand,  in  one  place,  and  the  finer  particles  are  deposited  in 
another,  making  the  clay.  The  lime  enters  partly  into  so- 
lution and  is  deposited  in  another  place,  and  so  on,  thus 
giving  us  sandy  soils,  clayey  soils  and  limy  soils,  all  differ- 
ing from  each  other  in  their  amount  and  proportion  of  the 
essential  fertilizing  constituents,  as  well  as  in  their  physical 
qualities,  —  the  sandy  and  gravelly  making  the  poorest 
soils  because  the  particles  consist  very  largely  of  quartz, 
and  the  remainder  being  poor  in  phosphoric  acid  or  potash. 
The  clay  soils  are  frequently  rich  in  minerals  containing 
potash,  and  poor  in  those  containing  lime  and  phosphoric 
acid ;  and  the  limestone  soils  are  poor  in  potash  and  rich 
in  lime,  and  frequently  in  phosphates.  In  addition  to  these 
soils,  there  are  those  that  are  made  up  largely  of  vegetable 
matter,  due  to  the  accumulation  of  decaying  growths. 
These  are  frequently  rich  in  nitrogen  and  poor  in  all  of  the 
essential  mineral  constituents. 

Hence  it  is  that  in  the  use  of  a  commercial  fertilizer, 
at  least  for  certain  crops,  a  knowledge  of  the  nature  of  soils 
in  respect  to  the  possible  deficient  element  is  important, 
in  order  that  those  which  exist  in  abundance  may  not  be 
added  to,  but  that  they  may  be  supplemented  by  such  an 
abundance  of  the  deficient  elements  as  to  permit  the  ac- 
quirement by  the  crops  of  those  necessary  for  a  maximum 
growth.  As  a  rule,  potash  is  a  very  essential  constituent 
of  manures  for  sandy  soils,  not  only  because  all  crops 
require  potash,  but  because  they  require  it  in  relatively 
large  amounts,  and  because  in  sandy  soils  it  is  liable  to 
exist  in  minimum  amounts.  Potash  fertilization,  therefore, 
is  especially  useful  on  sandy  soils.  On  the  other  hand,  in 
clay  soils,  which,  as  a  rule,  contain  a  very  considerable 
proportion  of  potash  as  compared  with  sandy  soils,  the 


194  Fertilizers 

deficient  element  may  be  either  phosphoric  acid  or  lime; 
and  if  these  are  supplied  in  abundance,  the  plant  will  be 
able  to  secure  the  necessary  potash.  In  a  limy  soil,  the 
lime  and  phosphoric  acid,  and  perhaps  the  potash,  may  be 
in  sufficient  abundance  to  cause  a  normal  growth  of  plant, 
yet  the  nitrogen  may  be  so  deficient  as  to  prevent  a  normal 
growth. 

Physical  imperfections  of  sandy  soils. 

If  it  were  possible  distinctly  to  classify  soils  in  respect 
to  their  lack  of  one  or  more  of  the  essential  constituents, 
it  would  be  an  easy  matter  to  formulate  rules  for  our 
guidance  in  the  fertilization  of  these  soils ;  but  such  is  not 
the  case.  Even  sandy  soils  vary  widely  in  their  chemical 
composition,  as  well  as  in  their  mechanical  or  physical 
properties,  and  certain  of  them  possess  such  a  physical 
character  as  to  make  it  impossible  to  grow  maximum  crops 
even  though  the  essential  elements  are  all  supplied  in 
sufficient  abundance.  The  constituent  particles  are  too 
coarse,  and  thus  make  the  soils  so  open  and  porous  that 
they  too  freely  admit  the  air,  water  and  warmth,  and  thus 
results  a  very  rapid  drying  and  heating  of  the  soil,  with  a 
premature  ripening  and  burning  of  the  crops.  The  phos- 
phates or  the  potash  compounds  applied  are  not  readily 
fixed,  and  suffer  an  immediate  loss  as  soon  as  rain  falls  in 
such  amounts  as  to  cause  a  leaching  from  them. 

Physical  imperfections  of  clay  soils. 

In  clay  soils,  the  physical  conditions  are  quite  the  reverse. 
All  clay  soils  do  not  have  the  same  general  composition, 
and  they  differ  widely  in  their  physical  qualities.  Certain 
of  them  possess  a  reasonably  good  texture,  and  permit  the 
absorption  of  the  food  applied,  as  well  as  its  gradual  dis- 


Methods  of  Use  of  Fertilizers  195 

tribution  throughout  the  mass  by  the  percolation  of  the 
water  through  them ;  while  certain  others  are  so  compact, 
owing  to  the  finely  divided  particles,  that  even  though  they 
were  abundantly  supplied  with  all  of  the  necessary  mineral 
constituents,  profitable  crops  could  not  be  grown  because 
the  roots  could  not  readily  penetrate,  and  because  the 
water  falling  upon  the  land  would  not  readily  pass  through, 
but  remain  upon  the  surface. 

In  the  case  of  soils  with  an  abundance  of  lime,  physical 
qualities  also  exercise  a  very  considerable  influence,  even 
though  there  is  a  sufficient  supply  of  all  of  the  fertility 
elements.  Certain  of  them  are  too  cold,  others  are  too  dry, 
and  the  mechanical  condition  is  such  as  to  prevent  the 
proper  and  uniform  growth  of  plants.  It  must  be  remem- 
bered, then,  that  only  general  rules  apply  in  the  use  of 
fertilizers  upon  soils  of  the  different  classes,  and  that  they 
are  modified  by  both  the  chemical  composition  and  the 
mechanical  condition  of  the  soils.  The  best  use  of  a  fer- 
tilizer —  that  is,  the  greatest  proportionate  return  of 
plant-food  in  the  crop,  all  things  considered  —  is  obtained 
from  its  application  upon  soils  that  possess  "condition," 
or  that  are  well  cultivated  or  managed.  Full  returns  can- 
not be  expected  when  they  are  applied  upon  soils  that  are 
too  wet  or  too  dry,  too  porous  or  too  compact,  or  too  coarse 
or  too  fine.  It  is  important  that  even  the  best  soils  should 
be  properly  prepared,  and  it  is  infinitely  more  important 
that  those  which  possess  poor  mechanical  condition  should 
be  improved  in  this  respect,  before  large  expenditures  are 
made  for  fertilizers. 

The  influence  of  previous  treatment  and  cropping. 

In  the  next  place,  the  previous  treatment  and  cropping 
of  soils  should  guide  in  the  use  of  fertilizers,  since  soils  of 


196  Fertilizers 

the  same  natural  character,  located  equally  well,  will  not 
always  show  the  same  results  from  the  application  of 
fertilizers,  because  in  the  one  case  the  cropping  has  been 
such  as  to  result  in  the  rapid  exhaustion  of  one,  rather  than 
the  three  specific  fertilizer  elements ;  while  in  the  other,  the 
cropping  may  have  been  quite  as  severe,  but  has  been  help- 
ful because  judicious  rotations  have  been  used  and  improved 
methods  practiced.  It  may  be  that  in  the  one  case,  there 
may  have  been  a  continuous  cropping  of  wheat,  for  exam- 
ple, and  only  the  grain  sold  from  the  farm,  in  which  case 
there  would  be  a  much  more  rapid  exhaustion  of  the  nitro- 
gen and  phosphoric  acid  than  of  the  potash;  and  if  this 
continuous  wheat-cropping  has  been  continued  for  a  long 
time,  an  application  of  the  phosphates  only  may  result  in 
quite  as  large  an  increase  in  crop  as  if  both  phosphates  and 
potash  salts  were  applied,  because  the  potash  exhaustion 
has  been  less  rapid  than  that  of  the  phosphoric  acid,  and 
the  addition  of  potash  would  simply  add  to  the  probably 
abundant  quantities  already  there.  On  the  other  hand, 
if  the  cropping  has  been  timothy  hay,  the  removal  of  the 
potash  would  have  been  greatly  in  excess  of  the  phosphoric 
acid,  and  consequently  a  fertilization  with  a  greater  propor- 
tion of  potash,  or  even  this  element  alone,  of  the  minerals, 
may  result  in  quite  as  large  returns  as  if  the  fertilization 
had  consisted  of  both  phosphoric  acid  and  potash.  In 
fact,  if  the  land  had  been  cropped  continuously  with 
tobacco,  cotton,  potatoes  or  other  crop,  there  is  likely  to 
be  a  much  larger  removal  proportionately  of  some  one 
element,  rather  than  proportionate  amounts  of  all.  This 
practice  results  in  a  disproportionate  removal  of  the  con- 
stituents, and  in  order  to  bring  the  land  back  to  its  capac- 
ity for  maximum  production,  or  to  equalize  matters  in  this 
respect,  it  is  necessary  to  add  to  the  soil  the  constituents 


Methods  of  Use  of  Fertilizers  197 

removed  in  amounts  in  excess  of  the  others.  On  the  other 
hand,  the  cropping  may  have  been  such  as  to  be  fully  as 
exhaustive  in  the  sense  that  the  total  quantity  of  constitu- 
ents removed  is  quite  as  great,  though  since  they  are 
removed  in  more  uniform  proportions,  the  period  of  prof- 
itable cropping  is  extended,  and  the  fertility  needed  in- 
cludes all  the  essential  elements,  rather  than  one  or  two. 
That  is,  the  grain,  hay  and  potatoes  may  have  been  grown 
in  rotation,  each  removing  one  or  the  other  in  greater 
proportion,  but  because  they  differ  with  each  crop,  no 
one  is  exhausted  before  the  other;  and  thus  when  the 
land  reaches  the  time  when  it  would  no  longer  profitably 
grow  those  crops,  an  application  then  of  all  of  the  con- 
stituent elements  would  result  in  a  greater  and  more 
profitable  increase  in  crop  than  if  the  fertilizer  contained 
one  constituent  only.  The  previous  treatment  and  crop- 
ping of  soils,  therefore,  is  an  important  guide  in  determining 
the  most  economical  method  of  fertilization. 

Furthermore,  in  this  matter  of  cropping  as  a  guide  to 
possible  need  of  fertilization,  it  must  be  remembered  that 
a  continuous  one-crop  practice  is  more  productive  of  total 
loss  of  constituents  than  a  practice  which  includes  such 
renovating  crops  as  clover,  or  one  which  permits  of  a  more 
constant  occupation  of  the  land,  since  in  the  former,  the 
introduction  of  clover  reduces  the  need  for  nitrogen  fer- 
tilization, and  in  the  latter,  the  vegetable  matter  is  not  so 
rapidly  used  up,  and  the  loss  of  mineral  constituents  by 
mechanical  and  other  means  is  very  much  reduced,  because 
of  the  constant  occupation  of  the  land. 

The  influence  of  character  of  crop. 

The  financial  result  from  the  application  of  fertilizers 
is  also  influenced  in  a  very  large  degree  by  the  character 


198  Fertilizers 

of  the  crop  itself,  whether  the  value  of  an  increase  in  crop 
as  great  as  can  be  expected  from  a  definite  application  is 
high  or  low;  and  on  this  basis,  crops  may  be  classified 
into  two  general  groups  :  first,  those  which  possess  a  high 
fertility,  and  which,  as  a  rule,  possess  a  relatively  low  com- 
mercial value ;  and  second,  those  which  possess  a  low  fer- 
tility value  and  a  relatively  high  commercial  value.  In  the 
first  class  are  included  the  cereal  and  forage  crops,  as  corn, 
oats,  wheat,  hay,  buckwheat,  cotton  and  tobacco,  and  in 
the  second  are  included  the  various  vegetable  and  fruit 
crops.  This  classification,  and  its  importance,  may  be 
illustrated  by  the  following  examples : 

A  ton  of  wheat,  at  $1  a  bushel,  will  bring  $33.33.  Its 
sale  removes  from  the  farm  38  pounds  of  nitrogen,  19  of 
phosphoric  acid  and  13  of  potash.  At  prevailing  prices 
for  these  constituents,  it  would  cost  $6.50  to  return  them 
to  the  farm. 

A  ton  of  asparagus  shoots,  at  10  cents  a  pound  bunch, 
will  bring  $200.  Its  sale  removes  from  the  farm  6  pounds 
of  nitrogen,  2  of  phosphoric  acid  and  6  of  potash,  which 
could  be  returned  for  but  little  more  than  $1. 

A  ton  of  timothy  hay  will  bring  $14.  Its  sale  removes 
from  the  farm  18  pounds  of  nitrogen,  7  of  phosphoric 
acid  and  28  of  potash,  amounts  that  would  cost  $4. 

A  ton  of  apples  will  bring  in  an  ordinary  season  $20. 
It  removes  less  than  3  pounds  of  nitrogen,  1  of  phosphoric 
acid  and  4  of  potash,  which  would  cost  less  than  60  cents 
to  return  to  the  land. 

It  is  thus  shown  that  crops  like  wheat  and  hay  possess 
a  relatively  low  commercial  value,  and  yet  carry  away, 
when  sold,  a  very  considerable  amount  of  the  fertilizing 
constituents,  while  vegetables  and  fruits,  as  illustrated  by 
the  asparagus  and  the  apples,  have  a  high  commercial  or 


Methods  of  Use  of  Fertilizers  199 

market  value,  and  carry  away  but  minimum  amounts  of 
the  fertilizing  constituents.  This  distinctive  character  of 
crops,  while  not  an  absolute  guide  as  to  the  profits  that  may 
be  obtained  from  the  use  of  fertilizers,  —  since  the  cost  of 
production  varies  widely  for  each  class,  —  is  instructive 
in  showing  that  those  of  a  low  commercial  value  are  more 
exhaustive  than  the  other  class,  or  those  of  a  high  market 
value,  and  is  certainly  suggestive,  pointing  out  the  neces- 
sity for  judgment  in  the  application  of  fertilizers  that  shall 
be  made  in  the  case  of  crops  of  the  different  groups. 

The  kind  of  farming,  whether  "extensive  or  intensive." 

Another  very  important  consideration,  and  one  which 
exercises  an  influence,  is  whether  the  farming  engaged  in 
is  "extensive"  in  its  character,  or  "intensive";  whether 
the  purpose  or  idea  is  simply  to  supplement  the  stores  of 
plant-food  in  the  soil,  or  whether  the  object  is  to  insure  an 
abundance  of  all  forms  of  constituents  under  all  reasonable 
conditions,  in  order  that  a  maximum  production  may  be 
secured. 

PLANTS  VARY  IN  THEIR  POWER  OF  ACQUIRING  FOOD 

In  the  next  place,  the  character  or  feeding  capacity  of 
the  plant  and  its  season  of  growth  should  be  considered, 
that  systematic  methods  may  be  adopted,  and  thus  not 
only  that  waste  of  fertilizing  materials  may  be  avoided, 
but  that  the  applications  may  be  made  at  such  times  and 
in  such  amounts  as  will,  other  things  being  equal,  promote 
the  greatest  increase  per  unit  of  applied  food. 

While  each  plant  possesses  individual  characteristics 
which  distinguish  it  from  all  others,  for  our  purpose  they 
may  again  be  classified  into  general  groups  which  possess 


200  Fertilizers 

somewhat  similar  characteristics,  particularly  as  to  their 
method  and  time  of  growth  and  their  capacity  for  acquir- 
ing food  from  soil  sources. 

Characteristics  of  the  cereal  group. 

The  cereals  possess  distinct  characteristics  of  growth. 
The  roots  branch  just  below  the  surface,  and  each  shoot 
produces  feeding  roots,  which  distribute  themeslves  in 
every  direction,  and  thus  absorb  food  from  the  lower  layers 
of  the  soil  as  the  plant  grows  older.  Because  of  their  wide 
root  system,  and  because  of  the  character  of  their  feeding 
rootlets,  they  are  able  readily  to  acquire  food  from  the 
insoluble  phosphates  and  potash  compounds  of  the  soil, 
though  they  are  unable  to  feed  to  any  extent  upon  the 
insoluble  nitrogen.  Furthermore,  inasmuch  as  the  most 
rapid  development  of  many  of  these  crops  takes  place 
early  in  the  summer,  before  the  conditions  are  favorable 
for  the  rapid  changing  of  organic  nitrogen  into  nitrates, 
they  are,  with  the  exception  of  Indian  corn  (maize), 
specifically  benefited  by  early  applications  of  nitrogen  in 
the  form  of  nitrate.  The  corn,  on  the  other  hand,  which 
makes  its  most  rapid  growth  after  the  other  cereals  are 
harvested,  —  in  July  or  August,  —  when  the  conditions 
are  particularly  favorable  for  the  development  of  nitrates, 
do  not  usually  require  as  large  proportions  of  nitrogen  as 
of  the  mineral  constituents,  particularly  the  phosphates. 
That  is,  wheat,  rye,  oats  and  barley  are  specifically 
benefited  by  the  early  application  of  quickly  available 
nitrogen. 

Characteristics  of  grasses  and  clovers. 

Forage  crops,  including  both  the  grasses  and  clovers, 
constitute  another  group,  in  so  far  as  their  use  is  concerned, 


Methods  of  Use  of  Fertilizers  201 

though  possessing  marked  distinguishing  characteristics. 
Of  the  grasses,  nearly  all  species  are  perennial,  though  their 
length  of  life  depends  upon  the  method  of  cropping  and 
upon  the  character  of  the  soil.  They  send  their  fibrous 
roots  into  the  surface  soil  in  the  same  manner  as  the  cereals, 
though  they  differ  from  them  in  forming  a  set  of  buds 
which  become  active  in  the  late  summer  and  develop  new 
roots  and  shoots.  They  resemble  the  cereals  in  their 
power  of  acquiring  mineral  food,  and  are  even  more  bene- 
fited by  the  application  of  nitrogen,  since  the  chief  object 
in  their  use  is  to  obtain  the  nitrogenous  substances  con- 
tained in  leaf  and  stem  in  the  form  of  pasture,  forage  or 
hay,  rather  than  the  matured  grain.  Hence,  nitrogen, 
which  promotes  this  form  of  growth,  is  an  important 
constituent,  and  under  any  conditions  there  should  be  a 
liberal  supply  provided. 

The  clovers,  on  the  other  hand,  are  not  perennial,  with 
the  partial  exception  of  "white"  or  "Dutch"  clover,  and 
with  this  exception  they  all  possess  a  taproot,  which  pene- 
trates downward,  and  as  it  descends,  throws  out  fibrous 
roots  into  the  various  layers  of  soil.  They  are  capable 
of  readily  acquiring  their  mineral  food,  both  because 
of  their  large  root  systems  and  because  of  the  charac- 
ter of  the  roots.  They,  however,  differ  in  one  very 
important  particular  from  the  cereals  and  grasses, 
in  that  under  proper  conditions,  as  already  pointed 
out  (p.  129),  they  are  capable  of  acquiring  their  ni- 
trogen from  the  air.  Thus  with  liberal  dressing  of 
only  phosphoric  acid  and  potash,  maximum  crops  may 
be  secured.  They  are  "nitrogen  gatherers,"  and  the 
tendency  of  their  growth  is  to  improve  the  soil  for  the 
nitrogen  consumers,  or  for  those  that  obtain  their  ni- 
trogen only  from  soil  sources. 


202  Fertilizers 


Root  crops. 

Another  class  of  plants,  differing  from  those  already 
described,  includes  the  root  crops,  as  beets,  mangels, 
turnips  and  carrots.  These  plants  cannot  make  ready 
use  of  the  insoluble  mineral  constituents  of  the  soil. 
Hence,  in  order  to  insure  full  crops,  they  must  be  liberally 
supplied  with  available  food.  Of  the  three  classes  of  fer- 
tilizing constituents,  the  phosphates  are  especially  useful 
for  turnips,  while  the  slower-growing  beets  and  carrots 
require  that  the  nitrogen  shall  be  in  quickly  available 
forms.  The  proper  fertilization  of  sugar  beets,  for  exam- 
ple, is  of  great  importance,  since  not  only  is  the  yield 
affected  by  fertilization,  but  the  quality  of  the  beet  for  the 
production  of  sugar. 

White  potatoes  and  sweet  potatoes,  the  one  a  tuber,  the 
other  an  enlarged  root,  constitute  another  class  which  does 
not  possess  strong  foraging  powers.  They  require  their 
food  in  soluble  and  available  forms,  and  with  suitable  soils 
potash  is  the  ingredient  that  is  especially  useful  in  the 
manures  applied. 

Markefyarden  crops. 

Another  group  of  crops  is  distinguished  as  a  class,  not  so 
much  because  of  their  peculiar  habits  of  growth  as  because 
of  the  objects  of  their  growth,  though  this  latter  fact  has  a 
very  important  bearing  upon  economical  methods  of  fer- 
tilization. This  class  includes  what  are  called  "market- 
garden  crops/'  as  lettuce,  beets,  asparagus,  celery,  turnips, 
cucumbers,  melons,  sweet  corn,  beans,  peas,  radishes  and 
various  others.  The  particular  object  in  raising  these  is  to 
secure  rapidity  in  growth,  and  thus  to  insure  high  quality, 
which  is  measured  by  the  element  of  succulence.  In  order 


PLATE  IX.  —Lima  Beans  and  Potatoes. 


FIG.  17.  —  NINETY-ACRE  FIELD  or  LIMA  BEANS  FOR  CANNING,  FREE- 
HOLD, NEW  JERSEY.     A  GOOD  EXAMPLE  OF  A  FIELD  TRUCK  CROP. 


FIG.  19.  —  ONE  TON  OF   HIGH-GRADE  FERTILIZER  USED  UPON  EARLY 
POTATOES  is  THE  COMMON  PRACTICE  AMONG  GROWERS  IN  NEW  JERSEY. 


Methods  of  Use  of  Fertilizers  203 

that  this  may  be  accomplished,  they  must  be  supplied 
with  an  abundance  of  available  plant-food,  and  since 
nitrogen  is  the  one  element  which  more  than  any  other 
encourages  and  stimulates  leaf  and  stem  growth,  its  use  is 
especially  beneficial  to  all  of  these  crops.  They  must  not 
lack  for  this  element  in  any  period  of  their  growth,  though, 
of  course,  a  sufficiency  of  minerals  must  be  supplied  in 
order  that  the  nitrogen  may  be  properly  utilized.  Because 
of  their  high  commercial  value,  the  quantity  of  plant-food 
applied  may  be  greatly  in  excess  of  that  for  any  other  of 
the  groups,  and  profits,  as  a  rule,  are  measured  by  this 
excess  rather  than  by  the  proportion  of  the  elements. 

Fruit  crops. 

Another  distinct  class  of  crops,  though  differing  materi- 
ally in  their  individual  characteristics,  as  well  as  in  their 
tune  and  period  of  growth,  are  the  fruits.  These  differ 
from  most  other  crops,  in  that  a  longer  season  of  prepara- 
tion is  required,  in  which  the  growth  may  be  so  directed 
as  to  prepare  the  plant  or  tree  for  the  proper  development 
of  a  different  kind  of  product,  namely,  fruit,  as  distinct 
from  grain  or  seed  in  the  cereals,  or  succulence  in  the 
vegetable  crops.  The  fruit  differs  in  its  characteristics 
from  the  ordinary  farm  crops,  in  that  its  growth  and  de- 
velopment require  a  little  different  treatment,  since  it  is 
necessary  that  there  shall  be  a  constant  transfer  of  food 
from  the  tree  to  the  fruit  throughout  the  entire  growing 
season.  The  growth  of  each  succeeding  year  of  tree  and 
fruit  is  dependent,  not  altogether  upon  the  food  acquired 
during  the  year,  but  as  well  upon  that  acquired  in  the 
previous  year,  and  which  has  been  stored  up  in  bud  and 
branches.  A  knowledge  of  the  habits  of  growth,  the  period 
of  growth  and  the  object  of  the  growth  of  this  class  is, 


204  Fertilizers 

therefore,  useful  as  a  guide  to  the  economical  supply  of  the 
essential  elements  of  growth.  These  crops  must  be  pro- 
vided with  food  that  will  encourage  a  slow  and  continuous 
rather  than  a  quick  growth  and  development. 

SYSTEMS  OF  FERTILIZING  SUGGESTED 

A  careful  review  of  the  foregoing  facts  furnishes  abun- 
dant evidence  of  the  impracticability  of  attempts  to  give 
information  concerning  the  use  of  fertilizers  that  will  apply 
equally  well  under  all  of  the  conditions  of  farming  that 
may  occur.  Nevertheless,  there  have  been  a  number  of 
methods  or  systems  of  fertilization  suggested,  each  of 
which  possesses  one  or  more  points  of  advantage. 

A  system  based  upon  the  specific  influence  of  a  single  element. 

The  one  which  has  perhaps  received  the  most  attention, 
doubtless  largely  because  one  of  the  first  presented,  and  in 
a  very  attractive  manner,  is  the  system  advocated  by  the 
celebrated  French  scientist,  George  Ville.  This  system, 
while  not  to  be  depended  upon  absolutely,  suggests  lines 
of  practice  which,  under  proper  restrictions  may  be  of 
very  great  service.  In  brief,  this  method  assumes  that 
plants  may  be,  so  far  as  their  fertilization  is  concerned, 
divided  into  three  distinct  groups.  One  group  is  specifi- 
cally benefited  by  nitrogenous  fertilization,  the  second  by 
phosphatic,  and  the  third  by  potassic.  That  is,  in  each 
class  or  group,  one  element  more  than  any  other  rules  or 
dominates  the  growth  of  that  group,  and  hence  each  par- 
ticular element  should  be  applied  in  excess  to  the  class  of 
plants  for  which  it  is  a  dominant.  In  this  system  it  is 
asserted  that  nitrogen  is  the  dominant  ingredient  for  wheat, 
rye,  oats,  barley,  meadow  grass  and  beet  crops.  Phos- 


Methods  of  Use  of  Fertilizers  205 

phoric  acid  is  the  dominant  fertilizer  ingredient  for  tur- 
nips, Swedes,  Indian  corn  (maize),  sorghum  and  sugar 
cane;  and  potash  is  the  dominant  or  ruling  element  for 
peas,  beans,  clover,  vetches,  flax  and  potatoes.  It  must 
not  be  understood  that  this  system  advocates  only  single 
elements,  for  the  others  are  quite  as  important  up  to  a 
certain  point,  beyond  which  they  do  not  exercise  a  con- 
trolling influence  in  the  manures  for  the  crops  of  the  three 
classes.  This  special  or  dominating  element  is  used  in 
greater  proportion  than  the  others,  and  if  soils  are  in  a  high 
state  of  cultivation,  or  have  been  manured  with  natural 
products,  as  stable  manure,  they  may  be  used  singly  to 
force  a  maximum  growth  of  the  crop.  Thus,  a  specific 
fertilization  is  arranged  for  the  various  rotations,  the  crop 
receiving  that  which  is  the  most  useful.  There  is  no  doubt 
that  there  is  a  good  scientific  basis  for  this  system,  and  that 
it  will  work  well,  particularly  where  there  is  a  reasonable 
abundance  of  all  of  the  plant-food  constituents,  and  where 
the  mechanical  and  physical  qualities  of  soil  are  good, 
though  its  best  use  is  in  "intensive"  systems  of  practice. 
It  cannot  be  depended  upon  to  give  good  results  where  the 
land  is  naturally  poor,  or  run  down,  and  where  the  physical 
character  also  needs  improvement. 

A  system  based  upon  the  necessity  of  an  abundant  supply  of 

the  minerals.  (Wagner  System.) 
Another  system  which  has  been  urged,  notably  by  Ger- 
man scientists,  is  based  upon  the  fact  that  the  mineral 
constituents,  phosphoric  acid  and  potash,  form  fixed  com- 
pounds in  the  soil,  and  are,  therefore,  not  likely  to  be 
leached  out,  provided  the  land  is  continuously  cropped. 
They  remain  in  the  soil  until  used  by  growing  plants,  while 
the  nitrogen,  on  the  other  hand,  since  it  forms  no  fixed 


206  Fertilizers 

compounds  and  is  perfectly  soluble  when  in  a  form  useful 
to  plants,  is  liable  to  loss  from  leaching.  Furthermore, 
the  mineral  elements  are  relatively  cheap,  while  the  nitro- 
gen is  relatively  expensive,  and  thus  the  economical  use 
of  this  expensive  element,  nitrogen,  is  dependent  to  a 
large  degree  upon  the  abundance  of  the  mineral  elements 
in  the  soil.  It  is,  therefore,  advocated  that  for  all  crops 
and  for  all  soils  that  are  in  a  good  state  of  cultivation,  a 
reasonable  excess  of  phosphoric  acid  and  potash  shall  be 
applied,  sufficient  to  more  than  satisfy  the  maximum  needs 
of  any  crop,  and  that  the  nitrogen  be  applied  in  active 
forms,  as  nitrate  or  ammonia,  and  in  such  quantities  and  at 
such  times  as  will  insure  the  minimum  loss  of  the  element 
and  the  maximum  development  of  the  plant.  The  supply 
of  the  mineral  elements  may  be  drawn  from  the  cheaper 
materials,  as  ground  bone,  tankage,  ground  phosphates 
and  iron  phosphates,  as  their  tendency  is  to  improve  in 
character ;  potash  may  come  from  the  crude  salts.  Nitro- 
gen should  be  applied  chiefly  as  nitrate  of  soda,  because  in 
this  form  it  is  immediately  useful,  and  thus  may  be  applied 
in  fractional  amounts,  and  at  such  times  as  to  best  meet 
the  needs  of  the  plant  at  its  different  stages  of  growth,  with 
a  reasonable  certainty  of  a  maximum  use  by  the  plants. 
Thus  no  unknown  conditions  of  availability  are  involved, 
and  when  the  nitrogen  is  so  applied,  the  danger  of  loss  by 
leaching,  which  would  exist  if  it  were  all  applied  at  one 
time,  is  obviated. 

This  method  also  possesses  many  advantages,  particu- 
larly where  the  "  intensive "  system  is  practiced,  though 
it  is  also  useful  in  quickly  building  up  wornout  soils,  or 
those  naturally  poor,  because  in  any  case  these  must  be 
provided  with  liberal  supplies  of  the  minerals,  and  when 
these  only  are  applied,  the  immediate  outlay  is  far  less 


Methods  of  Use  of  Fertilizers  207 

than  if  the  expensive  element,  nitrogen,  were  included ;  and 
a  greater  economy  in  the  use  of  nitrogen  is  accomplished  if 
it  is  added  in  small  amounts  when  required.  Besides,  in 
the  improvement  of  soils,  the  liberal  application  of  the  min- 
erals is  conducive  to  an  abundant  growth  of  the  legumes, 
which  are  able  to  acquire  their  nitrogen  from  the  air,  thus 
reducing  to  some  extent  the  outlay  for  this  expensive  ele- 
ment. This  system  is  strongly  recommended  where  cheap 
phosphatic  and  potassic  materials  are  readily  accessible,  as 
is  the  case  in  those  countries  where  it  is  successfully  used. 

A  system  based  on  the  needs  of  the  plants  for  the  different 
elements  as  shown  by  chemical  analysis. 

Another  system  of  fertilization  is  based  upon  the  theory 
that  the  different  plants  should  be  provided  with  the  essen- 
tial elements  in  the  proportions  in  which  they  exist  in  the 
plants,  as  shown  by  chemical  analysis.  Different  formulas 
are,  therefore,  recommended  for  each  crop,  the  constituents 
of  which  are  so  proportioned  as  to  meet  its  full  needs. 
This  method,  if  care  is  taken  to  supply  an  abundance  of 
all  the  necessary  constituents,  may  result  in  a  complete 
though  perhaps  not  an  economical  feeding  of  the  plant, 
since  it  assumes  that  a  plant  which  contains  a  larger  amount 
of  one  constituent  than  of  another  requires  more  of  that 
constituent  in  the  fertilizer  than  of  the  others.  It  does 
not  take  into  consideration  the  fact  that  the  plant  which 
contains  a  larger  amount  of  one  element  than  another 
may  possess  a  greater  power  of  acquiring  it  than  one  which 
contains  a  smaller  amount. 

Neither  does  this  system  take  into  consideration,  as  al- 
ready pointed  out  (p.  199),  that  the  period  or  time  of  growth 
of  the  plant  also  exercises  a  considerable  influence  in  indi- 
cating the  capability  of  the  plant  to  acquire  its  necessary 


208  Fertilizers 

food  from  the  stores  of  the  soil,  as  may  be  illustrated  by 
wheat  and  Indian  corn,  which  both  contain  a  relatively  high 
I  content  of  nitrogen.  Under  good  conditions  of  soil,  wheat 
is  specifically  benefited  by  heavy  dressings  of  quickly  avail- 
able nitrogen.  Corn  is  not,  and  one  reason  is,  that  they 
possess  different  powers  of  acquiring  food,  due,  to  a  con- 
siderable extent,  to  the  difference  in  their  time  of  growth, 
as  well  as  to  the  period  or  time  of  their  most  rapid  growth. 
This  method  may,  however,  be  applied  with  very  great 
advantage  in  greenhouse  work,  or  in  growing  market- 
garden  crops,  where  the  amounts  in  the  soil  are  not  re- 
garded as  of  importance,  and  excessive  amounts  of  all  are 
added.  The  system  has  been  elaborated  to  a  great  degree 
of  nicety  for  the  growing  of  greenhouse  crops,  flowers  and 
foliage  plants,  so  much  so  that  now  artificial  manure  car- 
tridges are  prepared,  which  contain  the  amounts  and  kinds 
of  food  shown  by  the  analysis  of  the  different  plants  to  be 
needed  for  their  growth  and  full  development.  "The 
manure  has  the  form  of  a  fine  powder,  enclosed  within  a 
metallic  wrapper,  and  firmly  compressed  into  the  shape  of 
a  cartouche  or  capsule,  cylindrical  in  form,  about  three- 
fourths  inch  across  and  one-half  inch  in  depth.  It  is 
simply  thrust  into  the  soil  of  the  pot  to  a  depth  of  one-half 
or  one  inch,  and  allowed  to  remain.  After  a  time  it  is 
found  that  the  fertilizer  gradually  disappears,  and  at 
length  nothing  is  left  but  the  little  pill-box-like  wrapper, 
which  originally  contained  the  mixed  fertilizing  powder."  l 

A  system  in  which  the  fertilizer  is  applied  to  the  "money 

crop'9  in  the  rotation. 

Another  system  is  also  recommended,  which  is  well 
adapted  for  "extensive"  farming,  where  the  majority  of 

1  "The  Gardener's  Chronicle,"  London,  England. 


Methods  of  Use  of  Fertilizers  209 

crops  which  are  grown  in  rotation  possess  a  high  fertility 
value  and  a  low  commercial  value,  and  where  one  crop  is 
regarded  as  the  chief  "money-maker."  The  system  de- 
mands that  to  this  crop  shall  be  applied  such  an  abundance 
of  plant-food  as  to  insure  a  continuous  feeding,  and  a  con- 
sequent maximum  production,  even  though  adverse  condi- 
tions intervene.  Thus  by  a  liberal  supply  of  food,  a  money 
crop  is  secured  which  is  as  large  as  climate  and  seasonal 
conditions  will  permit,  though  which  does  not  require  all 
of  the  food  applied.  Hence  the  residue  may  be  depended 
upon  to  fully  nourish  the  remaining  crops  in  the  rotation, 
or  at  least  the  immediately  succeeding  ones,  thus  saving 
direct  outlay  for  them.  This  system  may  be  illustrated 
as  follows : 

On  soils  in  good  physical  condition,  and  naturally  well 
adapted  for  growing  potatoes,  this  crop  is  selected  as  the 
"money-maker"  in  the  rotation,  which  consists  of  corn, 
potatoes,  wheat,  clover  and  hay.  The  potato  crop  is 
fertilized  so  liberally,  say  with  1500  pounds  to  the  acre, 
of  a  fertilizer  containing  — 

Nitrogen 4% 

Phosphoric  acid 8% 

Potash 10% 

as  to  insure  its  maximum  growth  under  average  conditions. 
The  removal  of  a  large  crop  would  still  leave  a  large  residue 
of  plant-food,  which  would  provide  the  following  wheat 
crop  with  at  least  all  of  the  mineral  elements  necessary  to 
produce  a  maximum  crop.  If  the  wheat  does  not  show 
vigorous  growth  in  the  spring,  it  is  lightly  top-dressed  with 
nitrate  of  soda,  which  not  only  feeds  it  directly  with 
nitrogen,  but  strengthens  and  invigorates  the  plant,  en- 
abling it  to  secure  the  minerals  needed.  The  removal  of  a 


210  Fertilizers 

large  crop  still  leaves  an  unused  residue,  upon  which  the 
clover  crop  following  is  also  able  to  make  a  maximum 
growth,  and  thus  three  crops  are  fertilized  with  the  one 
application.  The  hay  is  either  fertilized  with  both  the 
minerals  and  nitrogen,  or  lightly  top-dressed  with  nitrogen 
early  in  the  spring.  The  yard  manure,  accumulated  from 
the  residue  of  straw,  hay  and  corn,  is  applied  to  the  corn, 
which,  being  a  gross  feeder,  is  able  to  obtain  from  this  an 
abundance.  Thus,  by  the  heavy  application  of  fertilizer 
upon  the  "money  crop,"  all  the  crops  in  the  rotation  are 
benefited. 

This  method  possesses  many  valuable  features,  and  is, 
perhaps,  quite  as  well  adapted  as  any  other  for  this  system 
of  farm  practice. 

An  irrational  system. 

The  most  expensive  and  irrational  system  of  all,  and 
one  more  commonly  practiced  than  any  other  in  general 
farming,  may  be  termed  the  "hit  or  miss"  system;  if  a 
"hit"  is  made,  there  is  a  profit,  if  a  "miss,"  the  loss  is 
trifling.  In  this  system,  no  special  thought  is  given  to  the 
character  of  the  crop  or  its  needs.  If  the  farmer  can 
afford  it,  he  purchases  a  fertilizer,  without  regard  to  its 
composition,  and  applies  it  in  very  small  amounts.  If  it 
happens  to  contain  that  element  which  is  particularly 
needed  for  the  plant  to  which  it  is  applied,  a  profit  is 
secured.  In  too  many  cases,  however,  the  constituents 
added  are  already  in  abundance  in  the  soil,  or  so  little  of 
the  fertilizer  is  used  as  to  preclude  any  profit. 

SUMMARY 

With  the  exception  of  this  last  system,  there  are  good 
features  in  all  of  these  suggested  methods  of  use,  and  it 


Methods  of  Use  of  Fertilizers  211 

rests  with  the  farmer  to  select  the  best  points  from  each, 
or  rather  to  use  the  suggestions  in  each  which  are  in  his 
judgment  more  applicable  to  his  conditions.  They  are 
all  based  upon  underlying  principles,  and  pre-suppose  a 
knowledge  of  them  on  the  part  of  the  farmer.  They  are, 
at  best,  but  guides  or  sign-posts  pointing  toward  better 
methods  in  the  use  of  fertilizers,  rather  than  absolute  rules 
to  be  followed  blindly. 

It  may  be  pointed  out  that  these  systems  do  not  take 
into  consideration  the  character  of  the  soil.  Vast  differ- 
ences exist  between  soils,  not  only  in  their  natural  content 
of  plant-food  but  also  in  their  physical  and  mechanical 
character,  which  is  so  important  in  the  retention  and  libera- 
tion of  plant-food.  Nor  do  these  systems  give  apprecia- 
tion to  rational  farm  practices  such  as  green-manuring 
and  liming  which  have  such  a  material  effect  upon  the  soil 
stores  of  plant-food.  In  view  of  these  facts  the  good 
points  of  the  various  systems  should  not  only  be  utilized 
but  they  should  also  be  fortified  by  experimentation.  A 
more  complete  discussion  of  simple  experiments  for  this 
purpose  may  be  found  in  the  following  chapter. 

The  suggestions  here  and  in  subsequent  chapters,  in 
reference  to  the  use  of  fertilizers,  are  formulated  from  the 
best  information  obtainable  by  the  writer,  and  mainly  from 
two  sources:  First,  the  results  of  experimental  inquiry, 
and,  second,  the  results  of  the  observation  and  experience 
of  practical  men.  In  no  case  can  absolute  rules  be  laid 
down.  Farmers  may  safely  rely  on  the  well-established 
principles,  but  each  must  remember  that  the  use  of  the 
principles  must  be  modified  according  to  his  own  condi- 
tions. 


CHAPTER  XII 
FERTILIZERS  FOR  CEREALS  AND  GRASSES 

IT  has  already  been  pointed  out  (p.  198)  that  these 
crops  are  classed  as  possessing  a  relatively  low  com- 
mercial value  and  a  relatively  high  fertility  value,  and 
that,  from  a  practical  standpoint,  in  any  fertilization  of 
them  a  possible  profitable  return  should  be  borne  in  mind. 
This  is,  of  course,  necessary  in  all  cases,  but  is  particularly 
necessary  where  an  increased  yield,  as  great  as  can  be 
expected  from  an  application  of  proper  fertilizing  materials, 
cannot  possibly  result  in  an  extraordinary  profit,  a  result 
quite  possible  with  certain  crops  of  the  opposite  class. 
The  possible  increase  in  yield,  also,  is  dependent  on  the 
conditions  of  soil  and  season,  and  if  these  latter  are  such 
as  to  forbid  a  maximum  increased  yield,  the  immediate 
profits  from  the  application  are  reduced  considerably. 

It  has  been  shown,  also,  by  careful  experiments  that, 
on  the  average,  at  least  one-third  of  the  nitrogen  applied 
to  these  crops,  although  contained  in  the  best  forms,  is  not 
secured  in  the  crop,  even  under  the  most  favorable  condi- 
tions ;  that  is,  in  any  case  certain  amounts  are  lost  through 
drainage,  the  growth  of  weeds  and  denitrification ;  and, 
further,  that  the  minerals  must  exist  in  the  soil,  or  must  be 
supplied  in  sufficient  excess,  otherwise  the  utilization  of 
the  nitrogen  by  the  plant  is  still  further  reduced.  The 
expense  of  fertilizer  to  the  unit  of  increase  in  these  crops 

212 


Fertilizers  for  Cereals  and  Grasses 


213 


is,  therefore,  relatively  greater,  even  under  the  best  con- 
ditions of  its  use.  A  bushel  of  wheat,  with  its  accom- 
panying straw,  will  contain,  for  example: 

Nitrogen If  Ibs. 

Phosphoric  acid f  lb. 

Potash li  Ibs. 

It  will  be  observed  that  the  amounts  of  fertilizer  ingre- 
dients contained  in  the  crop  are  such  that  if  the  seasonal 


Fio.  14.  —  GRAIN  DRILL  WITH  FERTILIZER  SOWER. 

The  grain  drill  with  fertilizer  sower  has  justly  come  into  very  general 
use.  It  sows  the  seed  and  evenly  distributes  fertilizer,  at  the  same  time 
covering  both  with  sufficient  soil. 

conditions  are  perfect,  so  that  the  maximum  of  the 
amounts  applied  are  recovered  in  the  crop,  the  cost  of 
fertilizers  to  a  bushel  of  increase  is  still  relatively  high, 
thus  showing  that  great  care  must  be  exercised  in  order 
that  a  direct  and  immediate  profit  may  be  secured. 
Nevertheless,  since  the  cost  of  preparing  the  land  and  of 
harvesting  the  crop  is  but  slightly  greater  for  a  large  crop 
than  for  a  small  one,  the  larger  returns  for  the  labor  very 


214  Fertilizers 

frequently  pay  well  for  the  application  of  the  material, 
even  though  the  margin  of  money  profit  is  small.  In 
crops  of  this  sort  therefore,  and  especially  when  grown 
on  the  "extensive"  plan,  an  important  point  to  be 
determined  is  whether  the  land  is  deficient  in  all  of 
the  constituents  for  grain  and  hay  growing,  or  whether 
only  one  or  two  are  lacking,  in  order  that  in  the  appli- 
cations made,  only  those  constituents  are  supplied  that 
are  necessary,  and  adding  to  an  excess  already  present 
is  thus  avoided,  with  a  consequent  saving  in  the  cost 
of  the  fertilizer. 

EXPERIMENTS  TO  DETERMINE  THE  LACKING  ELEMENT 

The  lacking  element  cannot  be  fully  determined,  except 
by  direct  experiments  by  the  farmer  himself.  That  is, 
no  general  principle  can  be  depended  on  as  an  absolute 
guide.  He  should  learn  whether  his  soil  is  deficient  in 
any  of  the  elements,  and,  if  so,  which  ones  should  be 
applied  to  the  different  crops  in  his  rotation.  A  careful 
study  along  this  line,  too,  will  show  whether  it  is  fertiliza- 
tion that  is  required  to  meet  seeming  deficiencies,  for  it  fre- 
quently happens  that  the  needs  of  the  soil  are  not  so  much 
for  added  plant-food  as  for  better  management  of  the 
soil  in  other  respects,  in  order  that  natural  supplies  may 
be  made  more  available. 

It  may  seem,  at  first  glance,  that  experimenting  should 
be  left  to  the  experiment  stations,  and  that  farmers 
should  be  advised  by  them  of  the  needs  of  their  soils  in 
respect  to  plant-food.  This  is  partly  true,  but  the  proper 
function  of  experiment  stations  is  to  establish  principles, 
the  application  of  which  must  be  left,  in  large  part  at 
least,  to  the  intelligence  of  those  who  are  to  utilize  them. 


Fertilizers  for  Cereals  and  Grasses  215 

The  farmer  must  study  his  own  conditions.  Scientific 
inquiry  has  established  the  facts  that  soils  differ  in  their 
content  of  the  different  plant-food  elements,  and  that 
those  of  practically  the  same  chemical  composition  differ 
in  respect  to  their  physical  qualities,  which  conditions 
exercise  an  important  influence  upon  the  availability  of 
the  constituents. 

This  experimenting  may  also  seem  to  be  a  trouble- 
some operation,  yet,  if  thoughtfully  managed,  it  will 
mean  but  little  extra  labor,  and  the  resulting  gain  may  be 
far  in  excess  of  the  cost  of  the  work.  For  example,  if  it  is 
shown  that  fertilization  under  certain  conditions  is  not 
needed,  and  therefore  not  profitable,  it  saves  possible 
outlay  at  once ;  if  it  shows  that  the  application  of  certain 
of  the  constituents  is  a  profitable  practice,  it  enables  the 
adoption  of  a  systematic  scheme  of  fertilization. 

A  scheme  for  plot  experiments. 

The  following  simple  scheme  of  plot  experimenting 
has  been  suggested,  and  it  admits  of  determining  many 
of  the  points  involved.  This  scheme  includes  ten  plots, 
in  which  three  are  to  be  cropped  without  manure,  as 
check  plots,  in  order  to  show  the  productive  capacity  of 
the  unmanured  land.  The  plots  may  vary  in  size,  though 
it  is  desirable  that  they  should  contain  at  least  one-twen- 
tieth of  an  acre,  and  that  they  should  be  long  and  narrow 
(one  rod  wide  and  eight  rods  long  is  a  size),  in  order  to 
include  as  many  inequalities  of  the  soil  as  possible ;  though 
in  any  case  land  as  uniform  as  possible  in  physical  and 
chemical  qualities,  and  fairly  representative,  should  be 
selected.  The  following  plan  permits  of  a  study  of  the 
effect  of  the  application  of  individual  constituents,  and 
of  their  various  combinations.  If  desired,  in  order  to  sim- 


216  Fertilizers 

plify  the  work  in  the  beginning,  only  the  first  four  plots 
need  be  taken.  This  will  reduce  the  labor,  and,  at  the 
same  time,  permit  a  study  of  the  soil's  deficiencies  in 
respect  to  single  elements  of  plant-food,  and  the  relative 
needs  of  the  different  crops  for  the  various  constituents. 

The  rate  of  application  to  the  acre  is  greater  than  would 
naturally  obtain  in  practice,  in  order  to  facilitate  the  dis- 
tribution of  the  fertilizer,  to  furnish  a  sufficient  abundance 
of  the  constituent,  and  to  provide  against  unfavorable 
conditions. 

Preferably,  the  application  should  be  made  broadcast, 
and  before  planting,  though  for  cultivable  crops  it  may  be 
applied  later  and  harrowed  into  the  soil. 

It  will  be  observed  that  the  amounts  of  fertilizer  are 
one  pound  to  the  square  rod,  or  multiple  thereof.  Thus, 
in  order  to  insure  an  equal  distribution  over  the  entire 
area,  it  may  be  roughly  divided  into  plots  of  a  square  rod, 
and  the  required  material  for  each  rod  applied  separately. 
Careful  weights  should  be  made  of  the  yields  of  the  dif- 
ferent plots,  as  a  basis  of  comparison.  The  same  ferti- 
lizers should  be  used  on  the  different  crops  of  the  rotations, 
and  as  interest  is  increased  in  the  work,  different  forms 
and  amounts  of  the  various  constituents  may  be  intro- 
duced. 

Results  that  may  be  attained. 

If  it  is  found  that  for  a  certain  crop  only  one  of  the 
applied  constituents  profitably  increases  the  yield,  then 
that  should  be  used  until  the  need  of  the  others  is  appar- 
ent. If  two  are  needed  to  accomplish  the  results,  use 
two,  and  so  on;  though  in  the  long  run,  or  as  the  prac- 
tice approaches  the  "intensive"  system,  all  will  doubt- 
less be  required.  In  "extensive"  farming  this  is  a  very 


Fertilizers  for  Cereals  and  Grasses  217 

PLAN  OP  EXPERIMENT  —  SIZE  OF  PLOTS,  ^  OP  AN  ACRE 

132' 


Plot  I. 

O5 

kill- 

Check  —  No  fertilizer. 

Plot  II. 

Nitrate  of  soda. 

8  pounds. 

Plot  III. 

Acid  phosphate. 

16  pounds. 

Plot  IV. 

Muriate  of  potash. 

8  pounds. 

Plot  V. 

Check  —  No  fertilizer. 

Plot  VI. 

Nitrate  of  soda. 
Acid  phosphate. 

8  pounds. 
16  pounds. 

Plot  VII. 

Nitrate  of  soda. 
Muriate  of  potash. 

8  pounds. 
8  pounds. 

Plot  VIII. 

Acid  phosphate. 
Muriate  of  potash. 

16  pounds. 
8  pounds. 

Plot  IX. 

Nitrate  of  soda. 
Acid  phosphate. 
Muriate  of  potash. 

8  pounds. 
16  pounds. 
8  pounds. 

Plot  X. 

Check  —  No  f  ertilizer. 

218  Fertilizers 

desirable  line  of  experimentation,  and  can  be  carried  out 
by  individual  farmers.  It  is  useful  not  only  in  showing 
the  deficiencies  of  the  soil  for  the  various  crops,  but  is 
educative  in  its  character,  as  it  familiarizes  the  farmer  with 
the  materials  that  are  used  in  making  fertilizers,  and 
encourages  exact  methods  of  work.  Since,  as  already 
stated,  the  need  very  frequently  is  not  so  much  for  added 
fertility  as  it  is  for  better  preparation  and  cultivation  of 
the  soil,  or  for  amendments  such  as  lime,  it  would  be  a 
desirable  practice  to  include  in  the  number  of  plots  here 
indicated  one  or  two  in  which  the  cultivation  of  the  soil 
was  made  more  perfect,  in  order  to  determine  whether 
the  need  is  for  more  fertility  elements  or  whether  it  is  for 
better  tillage,  the  effect  of  which  is  to  render  more  of  the 
soil  constituents  available  to  the  plant.  One  or  two  to 
which  lime  is  added  may  be  advisable,  in  order  to  deter- 
mine whether  this  substance  is  needed  either  to  correct 
acidity  or  to  make  available  otherwise  unusable  com- 
pounds. This  method,  while  particularly  desirable  where 
"extensive"  methods  of  practice  prevail,  is  of  less  im- 
portance where  the  aim  is  to  grow  maximum  crops,  in 
which  case  both  the  crop  and  its  rotation  are  to  be  con- 
sidered, and  the  needs  of  the  plant  rather  than  the  de- 
ficiencies of  the  soil  require  first  attention. 

The  results  of  experiments  which  have  been  conducted 
with  great  care  in  a  number  of  states  show  that  where 
"extensive"  methods  are  practiced  certain  elements 
need  not  be  added  in  the  fertilizers ;  that  is,  that  the  soil 
contains  such  an  abundance  of  them  that  the  plant  is 
able  to  obtain  a  full  supply,  at  least,  for  a  long  time.  For 
example,  it  has  been  shown  that  on  the  chief  sugar-pro- 
ducing soils  of  Louisiana  and  Mississippi,  and  the  cotton 
soils  of  Georgia  and  Texas,  the  addition  of  potash  has  been 


Fertilizers  for  Cereals  and  Grasses  219 

of  less  importance  in  the  past  than  the  other  elements,  and 
it  frequently  does  not  need  to  be  included  in  the  fertilizer, 
while  phosphoric  acid  is  always  needed. 

The  results  of  field  experiments  on  this  plan  in  New  Jer- 
sey, on  reasonably  good,  loamy  soils,  indicate  that  phos- 
phoric acid  and  potash  are  of  much  more  importance  in 
fertilizers  for  corn  than  nitrogen,  whereas  upon  sandy 
soils,  nitrogen  and  potash  are  of  relatively  more  impor- 
tance than  phosphoric  acid;  that  is,  even  where  "exten- 
sive" practice  is  used  there  are  conditions  where  one  or 
more  of  the  elements  are  not  required  in  order  to  secure 
maximum  crops,  which  eliminates  the  necessity  for  an 
immediate  outlay  for  those  constituents  that  are  not 
lacking.  Where  experiments  of  this  sort  have  not  been 
carried  out  and  the  specific  needs  determined,  it  becomes 
necessary  to  assume  that  all  of  the  constituents  are 
required,  and  to  apply  the  amounts  and  proportions  of 
those  which  the  general  considerations  of  the  soil,  season, 
climate  and  crop  would  seem  to  demand. 

As  already  pointed  out,  the  methods  of  fertilization 
here  suggested,  though  in  many  instances  apparently 
positive,  are  not  to  be  interpreted  as  absolute  rules,  but 
rather  used  as  guides,  based  upon  the  best  information 
that  it  has  been  possible  to  obtain,  both  as  a  result  of 
scientific  inquiry  and  of  practical  experience. 

THE  IMPORTANCE  OF  SYSTEM  IN  THE  USE  OF  FERTILIZERS 

The  following  rotation  is  assumed,  in  order  to  show 
the  necessity  of  a  definite  system  of  work,  which  is  quite 
as  important  in  this  branch  of  farming  as  in  many  others 
in  which  system  is  apparently  more  essential,  —  though 
in  fact  it  is  quite  as  necessary  to  observe  a  definite  system 


220  Fertilizers 

in  the  feeding  of  plants  as  in  the  feeding  of  animals  with 
the  plants. 

ILLUSTRATION  OP  A  ROTATION 

First  year maize  (corn) 

Second  year oats 

Third  year wheat 

Fourth  year clover  and  timothy 

Fifth  year timothy  hay 

Indian  corn  exhaustive  of  the  fertility  elements. 

Since  in  rotations  of  this  sort  a  fair  number  of  live 
stock  is  usually  kept,  a  considerable  amount  of  ma- 
nure is  made,  which  should  be  carefully  cared  for  and 
used,  as  it  contributes  materially  to  the  success  of  the 
plan.  The  manure  may  be  used  in  part  on  land  for 
corn,  and  should  be  spread  broadcast,  practically  as 
fast  as  made  during  the  fall,  winter  and  early  spring. 
Corn,  because  it  is  a  gross  feeder,  and  because  it  makes 
most  of  its  growth  during  the  summer  season,  when  ac- 
tivities in  the  soil  are  most  rapid,  is  able  to  appropriate 
from  the  coarse  manures  a  larger  proportion  of  the  con- 
stituents than  would  be  possible  for  crops  which  make 
their  greatest  growth  earlier  or  later  in  the  season.  In 
the  summer,  too,  the  conditions  are  most  favorable  for 
nitrification,  and  soils  which  possess  a  fair  content  of  vege- 
table matter  are  usually  able  to  furnish  the  nitrogen  needed 
in  addition  to  that  supplied  in  the  organic  manures,  par- 
ticularly in  the  middle  and  southern  states.  The  consid- 
erable amounts  of  potash  required  for  the  growth  of  stalks, 
and  the  phosphoric  acid  for  the  formation  of  grain,  demand 
that  a  liberal  supply  of  these  constituents  be  provided, 
and  the  fertilizer  for  the  corn  should,  therefore,  contain 
an  abundance  of  available  phosphoric  acid  and  of  potash. 


PLATE  X.  —  Fertilizers  and  Tomatoes. 


FIG.  20.  —  EARLY  TOMATOES  GROWN  IN  LIGHT,  SANDY  SOIL,  THORO- 
FARE,  NEW  JERSEY. 


FIG.  21.  —  GROWTH  or  CLOVER  ALONG  TOMATO  Rows  HEAVILY  FER- 
TILIZED THE  PRECEDING  YEAR,  MOORESTOWN,  NEW  JERSEY. 


Fertilizers  for  Cereals  and  Grasses  221 

A  crop  of  50  bushels  of  shelled  corn  to  the  acre,  with 
the  accompanying  stalks,  will  remove,  on  the  average, 
80  pounds  of  nitrogen,  29  of  phosphoric  acid  and  55  of 
potash.  It  is  an  exhaustive  crop.  A  fertilizer,  therefore, 
that  would  furnish  30  pounds  of  phosphoric  acid  and  40  of 
potash  would  be  regarded  as  a  fair  dressing  for  land  of 
medium  quality,  provided  a  liberal  application  of  manure 
had  been  made  to  the  land.  A  part  of  the  phosphoric 
acid,  at  least,  should  be  in  a  soluble  form,  in  order  to  supply 
the  early  needs  of  the  crop.  The  remainder  may  consist 
of  ground  bone  or  tankage,  if  the  phosphoric  acid  in  these 
can  be  obtained  more  cheaply,  since  they  will  decay 
rapidly  enough  to  supply  the  demands  for  the  later  growth. 
The  potash  may  be  either  muriate  of  potash  or  kainit, 
though  the  former  is  preferable  if  it  is  applied  in  the  drill, 
which  is,  if  used  in  these  amounts,  a  perfectly  safe  practice 
so  far  as  injury  to  the  plant  is  concerned ;  though  ferti- 
lizers containing  large  amounts  of  potash  salts  are  prefer- 
ably applied  broadcast  on  raw  ground  of  a  clayey  nature, 
and  well  worked  into  the  soil,  thus  insuring  a  good  distri- 
bution. The  cost  of  an  application  of  this  sort  will  be 
relatively  small,  and  the  minerals  added  will  be  more 
than  sufficient  to  provide  for  a  considerable  increase  in 
crop. 

This  recommendation  is  general  and  applies  more  par- 
ticularly to  soils  of  high  natural  fertility.  The  soil,  crop- 
ping system  and  method  of  manuring  have  much  to  do 
with  the  fertilization  of  corn.  If  the  land  is  light  and 
sandy,  nitrogen  should  be  added,  even  though  it  has  re- 
ceived a  good  dressing  of  yard  manure,  as  these  lands  are 
usually  deficient  in  this  element,  and  organic  forms  are 
usually  quite  as  useful  as  the  soluble  nitrate  or  ammonia, 
since  the  seasonal  conditions  during  the  period  of  growth 


222  Fertilizers 

are  favorable  for  the  rapid  change  of  the  nitrogen  in  mate- 
rials of  good  quality,  like  blood,  concentrated  tankage, 
or  cotton-seed  meal,  into  nitrates.  The  amounts  of 
nitrogen  needed  would,  under  ordinary  conditions,  be  sup- 
plied by  100  pounds  of  high-grade  blood,  or  200  pounds 
of  cotton-seed  meal,  or  by  deriving  equal  parts  of  the 
nitrogen  from  nitrate  of  soda  and  tankage.  Other 
changes  are  also  required  according  to  the  cropping  system. 
In  the  rotation  mentioned  above  corn  follows  a  timothy, 
which,  if  properly  top-dressed  each  spring,  supplies  a  large 
amount  of  organic  matter,  and  fertilizer  may  be  used  in 
smaller  quantity,  and  a  smaller  amount,  especially  of 
the  more  slowly  available  nitrogen,  may  be  included  in 
the  mixture.  The  same  is  true  if  a  rank  leguminous  cover- 
crop  is  plowed  under  or  if  the  ground  is  heavily  manured. 
If  corn  is  grown  for  grain  one  year  and  silage  the  next,  a 
more  abundant  application  should  be  made  the  second 
year ;  20  pounds  of  nitrogen,  30  of  phosphoric  acid  and  40 
of  potash  is  none  too  liberal. 

Whatever  the  practice  of  cropping,  in  this  matter  of 
fertilizing,  it  must  be  remembered  that  weeds  appropriate 
plant-food  quite  as  readily  as  the  corn,  wherefore  in  order 
to  obtain  the  best  results  from  the  fertilizers  added,  clean 
cultivation  should  be  practiced. 

Oats. 

For  the  oat  crop  that  follows  corn,  and  which  makes 
its  best  growth  early  in  the  season,  before  nitrification 
is  rapid,  quickly  available  forms  of  nitrogen  are  very 
desirable;  and  inasmuch  as  the  oats  require  an  abun- 
dance of  phosphates,  a  fertilization  with  phosphoric 
acid  is  also  essential.  Hence,  fertilizers  consisting  of 
mixtures  of  nitrate  of  soda  and  superphosphates  have 


Fertilizers  for  Cereals  and  Grasses  223 

proved  of  great  value  for  this  crop.  An  application  of 
8  pounds  of  nitrogen  and  18  of  phosphoric  acid,  or  200 
pounds  to  the  acre  of  a  mixture  of  50  pounds  of  nitrate 
of  soda  and  150  of  acid  phosphate,  has  proved  quite  as 
profitable  on  medium  soils  as  heavier  applications,  mainly 
because  the  oat  crop  is  a  less  certain  one  than  corn ;  be- 
sides, it  frequently  suffers  severe  losses  in  harvesting,  which 
increase  the  risk  from  an  expensive  fertilization.  The 
application  of  potash  is  not  so  necessary  if  added  in  the 
fertilizer  for  corn,  as  suggested,  except  on  light,  sandy 
soils. 

It  is  not  a  profitable  practice  to  use  much  manure  in 
oats  land,  if  any,  because  it  is  liable  to  cause  a  stalky 
growth  and  subsequent  lodging  and  loss  in  harvest,  and 
furthermore,  it  may  be  utilized  so  much  more  profitably 
for  corn  or  some  other  crop  which  makes  more  of  its  growth 
in  mid-summer  when  the  soil  activities  are  at  their  greatest. 

Barley. 

The  fertilizer  requirements  of  barley  are  similar  in 
many  ways  to  those  of  oats,  although  greater  care  should 
be  used  in  the  application  of  nitrogen,  especially  should 
the  object  of  their  growth  be  for  malting.  For  this  pur- 
pose, a  plump,  heavy,  well-ripened  grain,  rich  in  nitrogen, 
is  required.  Too  rank  a  growth  of  straw,  caused  by  an 
abundance  of  nitrogen,  is  of  ten  accompanied  by  immaturity 
of  grain ;  besides,  in  moist  seasons  it  is  also  likely  to  assist 
in  the  promotion  of  rust. 

A  fertilizer,  therefore,  which  will  help  to  avoid  these 
dangers,  and  at  the  same  time  supply  the  needs  of  the 
plant,  may  be  made  up  of  50  pounds  of  nitrate  of  soda, 
150  of  acid  phosphate  and  25  of  muriate  of  potash  to  the 
acre.  This  mixture  used  at  the  time  of  seeding  will  supply 


224  Fertilizers 

the  needed  minerals  and  sufficient  nitrogen  to  give  the 
plants  a  good  start.  From  three  weeks  to  a  month  after 
seeding,  an  application  of  50  to  75  pounds  of  nitrate  of 
soda  to  the  acre  will  help  to  insure  a  proper  development 
and  maturity,  and  provide  for  the  largest  yield  of  grain 
without  injuring  the  quality  for  malting  purposes. 

Wheat.     (See  Fig.  15,  Plate  VIII.) 

The  fertilizing  of  wheat  will  depend  largely  upon 
the  treatment  of  preceding  crops.  For  wheat  following 
the  oats  crop,  the  remainder  of  the  manure  may  be  ap- 
plied before  plowing,  well  harrowed  into  the  surface  soil, 
and  a  fertilizer  rich  in  available  phosphoric  acid,  and  con- 
taining only  a  sufficient  amount  of  nitrogen  in  available 
forms  to  insure  a  good  fall  growth  applied.  When  the 
land  has  been  well  fertilized  for  previous  crops,  a  dissolved 
animal  bone  superphosphate  is  an  excellent  fertilizer, 
because  it  contains  the  elements,  phosphoric  acid  and 
nitrogen,  in  good  forms  and  proportions.  Dissolved  bone, 
however,  is  rather  scarce  and  an  expensive  source  of  plant- 
food,  and  a  mixture  composed  of  25  pounds  of  nitrate  of 
soda,  75  of  ground  bone,  200  of  acid  phosphate  and  25 
of  muriate  of  potash  will  give  quite  as  satisfactory  results. 
If  more  nitrogen  is  needed  than  is  provided  by  200  to 
300  pounds  of  this  fertilizer  in  order  to  mature  the  crop, 
which  is  frequently  the  case,  particularly  if  the  winter  has 
been  severe,  or  if  the  land  is  light,  it  may  be  applied  in  the 
spring,  and  preferably  in  the  form  of  a  nitrate,  which  dis- 
tributes readily,  and  is  immediately  available,  advantages 
not  possessed  by  other  forms.  At  this  period  of  its  growth, 
the  crops  need  to  make  a  rapid  appropriation  of  nitroge- 
nous food,  though  the  conditions  are  not  yet  favorable  for 
the  change  of  nitrogenous  organic  compounds  in  the  soil 


Fertilizers  for  Cereals  and  Grasses  225 

into  the  available  nitrate.  The  top-dressings  should 
be  made  as  soon  as  the  crop  has  been  well  started,  and 
should  range  from  75  to  150  pounds  to  the  acre,  according 
to  the  character  of  the  soil  and  previous  fertilization. 
The  better  the  natural  character  of  the  soil  and  its  treat- 
ment, the  larger  the  dressing  that  may  be  applied  with 
possible  profit,  though  in  no  case  should  it  exceed  the  larger 
amount.  In  many  cases  it  is  advisable  to  make  the  spring 
application  of  nitrate  of  soda  at  intervals  of  two  weeks  or 
more. 

Rye. 

Rye  is  often  used  in  this  rotation,  especially  when  a 
poor  field  comes  around,  because  it  is  often  considered  a 
scavenger.  In  spite  of  this  it  is  a  crop  which  responds  to 
good  cultivation  and  fertilization.  The  use  of  a  ferti- 
lizer, rich  in  phosphoric  acid  and  available  nitrogen,  is 
especially  recommended.  An  application  of  50  pounds 
of  nitrate  of  soda,  200  of  acid  phosphate  and  25  of  muriate 
of  potash  should  supply  ample  food  to  insure  a  good  fall 
growth. 

In  order  to  provide  an  abundance  of  available  nitrogen 
for  a  maximum  crop  of  both  straw  and  grain,  the  rye 
should  be  top-dressed  in  spring  with  at  least  100  pounds  of 
nitrate  of  soda  to  the  acre,  broadcast,  just  as  soon  as  the 
plants  start.  At  this  season  of  the  year,  the  requirements 
of  the  plant  are  the  greatest,  and  the  supply  of  available 
nitrogen  in  the  soil  very  meager ;  hence  such  an  applica- 
tion fully  meets  the  special  needs  of  the  plants  for  nitrogen. 

Clover. 

There  are  a  number  of  types  of  clover  which  are  sown 
in  wheat  when  the  ground  is  honeycombed  in  spring  and 
Q 


226  Fertilizers 

follow  it  as  a  crop.  Among  these,  red,  mammoth  red, 
alsike  and  white  clover  should  be  mentioned.  "As 
clover  is  a  legume,  it  is  not  usually  benefited  by  the  addi- 
tion of  nitrogenous  manures,  except  in  the  early  stages 
of  growth.  On  soils  not  well  supplied  with  vegetable 
matter,  manures  are  very  beneficial,  primarily  in  correct- 
ing the  deficiencies,  and  in  providing  a  more  favorable 
medium  for  the  development  of  specific  bacteria.  The 
size  of  the  crop  will  be  measured  to  some  extent,  also,  by 
the  abundance  of  mineral  elements,  thus  enabling  the  plant 
to  employ  to  full  advantage  its  capability  of  gathering 
nitrogen.  In  many  cases,  particularly  on  soils  that  are 
likely  to  heave,  a  mulch  of  manure  is  very  beneficial  as  a 
protection."  An  application  of  100  pounds  of  acid  phos- 
phate and  50  of  muriate  of  potash  or  one  which  will  fur- 
nish 14  pounds  of  phosphoric  acid  and  25  pounds  of 
potash  to  the  acre  marks  the  minimum  dressing,  and  it 
may  be  applied  with  advantage  immediately  after  the 
wheat  is  harvested. 

Timothy.     (See  Fig.  16,  Plate  VIII.) 

The  timothy,  the  next  crop  in  the  rotation,  is  a  member 
of  the  grass  family,  and  is  especially  benefited  by  nitrog- 
enous fertilization,  and  top-dressings  in  the  spring  with 
nitrate  of  soda  have  proved  of  great  value  on  soils  well 
supplied  with  minerals,  though  experienced  farmers  have 
learned  that  better  results  are  obtained  if  the  minerals 
are  applied  with  the  nitrate,  thus  insuring  a  better  growth 
and  development  of  plant.  A  mixture  made  up  of  100 
pounds  of  nitrate  of  soda,  150  pounds  of  acid  phosphate 
and  50  pounds  of  muriate  of  potash,  at  the  rate  of  300 
pounds  to  the  acre,  is  now  used  by  many  successful  hay- 
growers.  In  an  ordinary  season,  such  an  application  may 


Fertilizers  for  Cereals  and  Grasses  227 

be  relied  upon  nearly  to  double  the  timothy  crop.  Under 
some  conditions  a  slight  change  of  the  mixture  is  advisable. 
Upon  heavy  soils  or  limestone  soils,  the  muriate  of  potash 
may  be  reduced  to  one-half  or  even  omitted  entirely.  The 
nitrate  of  soda  may  be  increased  in  mixtures  for  the  same 
type  of  soil  to  150  pounds,  but  care  should  be  exercised 
in  this  matter  because  too  large  a  proportion  of  nitrate  of 
soda  is  liable  to  cause  too  rapid  a  growth  and  subsequent 
lodging  and  "firing/'  It  is  often  stated  that  nitrate  of 
soda  causes  a  light,  leafy  hay,  but  this  is  only  true  when  the 
mixture  is  not  properly  balanced.  It  is  not  profitable  to 
top-dress  timothy  sods  unless  there  is  a  sufficient  number 
of  plants  on  the  ground  to  make  efficient  use  of  the  plant- 
food  which  is  immediately  available  and  subject  to  loss 
if  not  used.  The  proportionate  increase  in  crop  would  be 
the  same,  but  the  increase  in  yield  would  not  be  large 
enough  to  show  a  profit  over  cost  of  application.  In 
every  instance  the  application  should  be  made  as  soon  as 
the  crop  has  well  started  in  the  spring. 

The  system  of  fertilization  here  outlined  is  not  to  be 
advocated  except  under  circumstances  where  it  is  not 
possible  or  practicable  to  supply  such  an  abundance  of 
plant-food  as  will  guarantee  a  maximum  production,  as 
in  "intensive"  practice,  in  which  the  yield  is  measured 
by  climatic  and  seasonal  rather  than  soil  conditions, 
but  rather  such  additions  as  will  return  a  profit  and  at 
the  same  time  tend  toward  the  improvement  of  soil. 
This  system  is  economical  in  the  use  of  nitrogen,  the 
most  expensive  element.  It  provides  a  sufficient  amount 
of  available  plant-food  to  insure  a  reasonable  increase 
in  crop,  and  it  is  well  adapted  to  lead  the  farmer  by  easy 
steps  from  the  "extensive"  to  the  "intensive"  system  of 
fanning. 


228  Fertilizers 

A  gain  of  fertility  by  the  rotation  system. 

Assuming  that  the  increased  yield  of  corn  is  20 
bushels,  with  accompanying  stalks,  of  wheat  10  bushels 
per  acre,  of  oats  15  bushels,  of  clover  J  ton  and  of 
timothy  J  ton,  the  amounts  applied  will  be  practically 
sufficient  to  furnish  all  of  the  potash  contained  in  this 
increase,  and  more  than  sufficient  to  meet  the  demands 
for  phosphoric  acid.  That  is,  by  this  system  there  has 
been  applied  in  the  materials  30  pounds  of  nitrogen,  64 
of  phosphoric  acid  and  80  of  potash.  While,  if  this  in- 
creased crop  was  secured,  the  following  amounts  would 
be  required:  71  pounds  of  nitrogen,  31  of  phosphoric 
acid  and  79  of  potash.  The  considerable  amounts  of 
plant-food  contained  in  the  yard  manure,  and  the  gain 
from  the  roots  and  stubble  of  the  clover,  serve  to  supply 
the  balance  of  nitrogen  required,  and  to  provide  a  store 
of  unused  residue  for  future  crops. 

The  method,  if  adopted,  would  be  more  rational,  and 
likely  to  result  in  more  satisfactory  returns  than  the 
one  now  generally  practiced,  namely,  to  purchase  with- 
out particular  regard  to  the  character  of  the  materials 
furnishing  the  constituents,  or  their  proportions,  and 
to  apply,  on  the  average,  even  less  per  acre  than  is 
here  recommended.  Assuming  that  200  pounds  to  the 
acre  of  the  average  corn  fertilizer,  showing  a  composi- 
tion of  2.5  per  cent  nitrogen,  8  of  phosphoric  acid  and 
5  of  potash,  were  applied  only  to  the  crops  corn,  oats 
and  wheat,  omitting  both  clover  and  timothy,  there 
would  have  been  added  15  pounds  of  nitrogen,  48  of 
phosphoric  acid  and  30  of  potash,  amounts  of  each  too 
small  to  provide  for  a  large  increase  in  crop,  provided  all 
were  needed. 


Fertilizers  for  Cereals  and  Grasses  229 

The  necessity  of  adding  more  plant-food  than  is  required 
by  a  definite  increase  in  crop. 

It  may  be  asked,  why  add  more  of  the  constituents 
than  is  necessary  to  provide  for  a  definite  increase  in 
crop?  Assuming  that  the  average  yield  of  the  land  is 
twenty  bushels  of  wheat  to  the  acre,  and  the  aim  is  to 
secure  thirty  bushels,  why  not  add  the  constituents  in 
the  amounts  and  proportions  necessary  to  provide  for 
this  extra  increased  yield,  rather  than  any  excess  of  these 
amounts?  The  answer  is,  that  in  order  that  such  a 
result  may  be  accomplished,  the  conditions  would  need 
to  be  absolutely  perfect,  so  that  the  plant  would  have  at 
its  command  the  amount  of  food  needed  each  day.  If  a 
period  in  the  growth  of  the  plant  should  be  so  wet  or  so 
dry  as  to  prevent  the  plants  from  acquiring  the  food 
necessary  for  their  continuous  growth,  there  would  be  no 
opportunity  for  them  to  gather  food  faster,  when  the 
better  conditions  followed  the  unfavorable  conditions,  and 
thus  to  overcome  the  ill  effects  of  the  period  of  partial 
starvation.  In  other  words,  if  there  were  only  sufficient 
food  to  supply  the  plant  under  normal  conditions  of  sea- 
son, the  plant,  after  a  period  of  time  during  which  there 
was  no  growth,  could  not  grow  faster  than  it  did  before, 
hence  it  could  not  catch  up  in  its  growth  and  make  a 
full  crop.  Furthermore,  the  plan  of  applying  only  that 
needed  for  the  increase  must  necessarily  assume  that  the 
plant-food  is  in  the  best  forms,  and  that  the  physical  con- 
ditions of  soil  are  so  perfect  as  to  cause  it  to  absorb  and 
retain  all  the  food  applied,  and  in  such  a  manner  as  to 
permit  it  to  be  readily  obtained  by  the  plant.  A  further 
advantage  is  to  enable  the  clover  plant  in  the  rotation 
to  fully  exercise  its  power  of  acquiring  nitrogen  from  the 


230  Fertilizers 

air.  Moreover,  if  properly  carried  out,  it  fulfils  the  idea 
of  successful  agriculture;  viz.,  the  production  of  profit- 
able crops,  while  at  the  same  time  not  reducing,  but 
increasing,  the  potential  fertility  of  the  soil. 

The  system  should  be  modified  if  no  farm  manures  are  used. 

In  this  rotation,  if  no  manures  are  available,  as  indi- 
cated, then  the  amounts  and  kinds  of  fertilizers  should 
be  somewhat  changed.  For  example,  if  it  was  necessary 
to  supply  the  corn  crop  with  a  sufficient  abundance  of  all 
the  elements  in  artificial  forms,  then  the  proportions  of 
nitrogen  should  be  somewhat  greater  and  the  total  amounts 
of  the  constituents  applied  to  the  different  crops  consider- 
ably increased.  For  corn,  a  mixture  consisting  of  20 
pounds  of  nitrogen,  30  of  phosphoric  acid  and  50  of  potash 
should  be  applied,  and  if  grown  upon  raw  ground  rather 
than  upon  sod,  it  would  be  desirable  to  still  further  in- 
crease the  nitrogen.  The  oats  could  be  fertilized,  as 
before  recommended,  while  the  wheat  should  have  an 
increased  supply  of  both  nitrogen  and  phosphoric  acid, 
—  double  the  amounts  recommended  when  used  with 
manure,  —  besides  an  addition  of  at  least  10  pounds  to 
the  acre  of  potash.  The  fertilizing  of  the  clover  and  tim- 
othy need  not  be  changed.  If,  in  a  rotation  of  this  char- 
acter, barley  were  substituted  for  oats,  and  rye  for  wheat, 
the  fertilization  need  not  be  materially  changed,  though 
the  rye  possesses  a  slightly  greater  power  of  acquiring 
phosphoric  acid  than  wheat,  and  the  nitrogenous  top- 
dressings  may  be  omitted,  unless  the  crop  is  grown 
primarily  for  straw  rather  than  for  grain.  The  barley 
is  also  less  able  to  acquire  its  phosphoric  acid  than  the 
oats,  and  is  especially  benefited  by  nitrogen,  though  care 
should  be  exercised  to  regulate  the  amounts  applied  in 


Fertilizers  for  Cereals  and  Grasses  231 

order  to  prevent  lodging,  which  affects  both  the  yield  and 
quality  of  the  grain.  If  in  the  rotation  the  timothy  hay 
is  omitted,  then  the  fertilization  for  the  corn  may  be 
reduced,  as  on  good  soils  the  yard  manure,  together  with 
the  plant-food  stored  in  the  surface  in  the  clover  sod,  will 
furnish  an  abundance. 


FERTILIZERS   FOR   A   SINGLE   CROP   GROWN   CONTINUOUSLY 

When  it  is  desirable  to  grow  any  one  or  all  of  these 
crops  continuously  (and  this  practice  may  be  followed 
with  advantage,  particularly  when  a  leguminous  catch- 
crop  is  seeded  with  the  main  crop,  which  insures  a  contin- 
uous occupation  of  the  land  and  also  provides  vegetable 
matter  and  nitrogen),  the  fertilization  would  naturally 
be  somewhat  different,  and,  as  a  rule,  would  require  more 
nearly  even  quantities  of  the  different  constituents.  For 
corn,  a  fertilizer  supplying  20  pounds  of  nitrogen,  40  each 
of  phosphoric  acid  and  potash,  would  provide  for  a  liberal 
increase  in  the  yield  from  year  to  year.  The  nitrogen 
should  preferably  be  in  good  organic  forms,  which  would 
decay  rapidly  enough  to  supply  the  needed  available  nitro- 
gen during  the  growing  season.  The  phosphoric  acid 
may  be  drawn  partly  from  superphosphates  and  partly 
from  organic  compounds,  as  ground  bone  and  tankage, 
provided  these  latter  may  be  secured  at  as  low  a  price 
as  the  superphosphate,  and  the  potash  applied  in  the  form 
of  a  muriate  or  kainit.  Fertilizers  may  be  applied  broad- 
cast and  well  harrowed  into  the  soil,  or  part  may  be  dis- 
tributed in  the  row  at  time  of  planting. 

If  a  catch  crop  were  seeded  to  be  used  as  green-manure, 
as,  for  example,  crimson  clover,  the  application  of  nitro- 
gen may  be  very  materially  reduced.  This  practice  has 


232  Fertilizers 

been  followed  with  advantage  in  the  middle  and  southern 
states. 

For  continuous  wheat-growing,  a  fertilizer  may  be 
used  at  time  of  seeding  which  supplies  10  pounds  of 
nitrogen,  40  of  phosphoric  acid  and  20  of  potash.  A 
small  part  of  this  nitrogen  would  better  be  in  the  form 
of  a  nitrate,  which  will  encourage  a  good  top-growth 
in  the  fall,  as  well  as  a  deep  root  system ;  the  phosphoric 
acid  should  be  soluble,  in  order  to  supply  the  immediate 
needs  of  the  young  plant,  and  the  potash  in  the  form  of  a 
muriate.  Such  an  application  would  provide  for  a  very 
considerable  increase  in  crop,  particularly  if  followed  in 
the  spring  by  a  top-dressing  of  100  pounds  to  the  acre  of 
nitrate  of  soda. 

The  top-dressing  with  nitrate  of  soda  is,  however, 
not  always  advisable.  The  chief  objection  to  its  use  is 
that  it  does  not  encourage,  but  frequently  seems  to  retard, 
the  growth  of  clover,  though  its  very  great  advantage  is 
that  it  encourages  the  deeper  rooting  of  the  wheat  and 
the  more  rapid  growth  of  grasses.  If  continuous  cropping 
of  wheat  is  practiced,  clover  should  be  seeded  with  it, 
in  order  that  the  ground  may  be  constantly  occupied, 
and  thus  prevent  leaching,  as  well  as  mechanical  losses 
of  fertility,  and  also  to  supply  vegetable  matter  containing 
nitrogen  for  the  succeeding  crop.  When  a  system  thus 
outlined  has  been  continued  for  a  few  years,  the  nitrogen 
in  the  fertilizer  may  be  largely  omitted. 

The  same  considerations  apply  to  rye  as  were  indicated 
for  wheat.  Oats  are  seldom  grown  as  a  continuous 
crop,  though  if  it  should  be  desirable,  a  fertilizer  furnish- 
ing at  least  20  pounds  of  nitrogen,  25  of  phosphoric  acid 
and  10  of  potash  would  be  a  good  dressing,  care  being 
taken  that  a  large  portion  of  the  nitrogen  exists  as  nitrate 


Fertilizers  for  Cereals  and  Grasses  233 

or  as  ammonia,  in  order  to  stimulate  and  strengthen  the 
early  growth  of  the  plant.  For  the  grass  crop,  or  con- 
tinuous mowing  land,  a  fertilizer  rich  in  nitrogen  and 
potash  should  be  applied.  A  good  application  in  the 
spring  may  consist  of  25  pounds  of  nitrogen,  15  of  phos- 
phoric acid  and  25  of  potash,  and  immediately  after  the 
hay  is  harvested  a  further  application  of  at  least  20  pounds 
of  nitrogen  and  30  each  of  phosphoric  acid  and  potash 
should  be  applied.  The  nitrogen  in  this  case  may  consist 
partly  of  organic  forms,  though  the  soluble  nitrogen  is 
to  be  preferred  as  top-dressings  where  it  can  be  procured 
at  such  a  price  as  to  make  it  comparable  with  other  forms. 
The  nitrogen  of  bone,  tankage  and  other  slower-acting 
forms  is  excellent  for  the  grasses,  though  these  should  be 
preferably  applied  and  well  worked  into  the  soil  previous 
to  seeding.  The  early  spring  application  should  consist 
largely  of  soluble  nitrogen,  both  to  encourage  a  rapid 
appropriation  of  this  element  by  the  plant  early  in  the 
season,  as  well  as  a  deeper  root-system,  and  consequently 
a  greater  drought-resisting  power,  and  also  to  provide 
the  elements  necessary  for  the  increased  crop.  The 
summer  or  later  application  stimulates  and  strengthens 
the  roots  for  the  coming  season.  If  an  aftermath  crop  is 
removed,  or  if  it  is  pastured,  a  further  application  may  be 
made  which  may  consist  largely  of  the  mineral  elements. 
This  fertilization  of  the  hay  crop  will  also  result  in  a  richer 
product,  for  an  abundant  supply  of  nitrogen  encourages  a 
larger  proportion  of  leaf  growth,  and  consequently  a  smaller 
proportion  of  stem,  containing  the  less  valuable  woody 
matter.  Lands  that  are  well  fertilized  in  this  way,  if 
properly  seeded  in  the  first  place,  may  make  profitable 
mowing  crops  for  a  long  series  of  years,  and  good  crops 
cannot  be  expected  unless  liberal  fertilization  is  practiced. 


234  Fertilizers 


FERTILIZERS  FOR  MEADOWS 

For  meadows  used  as  pastures,  a  more  liberal  appli- 
cation of  the  mineral  elements  is  recommended,  since 
an  abundance  of  these  encourage  the  growth  of  the 
clovers,  which  make  a  richer  herbage  than  the  grasses. 
Heavy  nitrogenous  fertilization  is  expensive,  and  en- 
courages the  growth  of  the  grasses  rather  than  the  clovers. 
Pasturing,  while  less  exhaustive  than  hay  cropping, 
nevertheless  results  in  the  gradual  depletion  of  fertility, 
and  an  abundant  growth  of  rich  pasturage  can  only  be 
secured  where  there  is  an  abundant  supply  of  available 
plant-food.  Mixtures  made  up  of  acid  phosphate,  ground 
bone  and  muriate  of  potash  in  equal  proportions  make 
very  good  dressings,  if  applied  in  sufficient  quantity,  300 
to  500  pounds  to  the  acre  annually.  The  ground  bone  is 
recommended  because  it  decays  slowly,  and  thus  fur- 
nishes a  continuous  supply  of  nitrogen  and  of  phosphoric 
acid.  The  application  should  preferably  be  made  both 
in  spring  and  in  late  summer,  in  order  to  secure  a  good 
growth,  as  well  as  to  encourage  the  introduction  of  the 
clovers.  Pastures  become  very  acid  in  time  and  the  ap- 
plication of  lime  is  important.  The  carbonate  form  or 
ground  limestone  usually  produces  best  results.  Appli- 
cations of  500  pounds  annually  or  a  single  application  of 
one  and  one-half  tons  every  five  or  six  years  should  be 
made.  If  caustic  lime  is  used,  an  application  of  1500 
pounds  every  four  or  five  years  should  be  sufficient,  though 
the  first  application  might  be  much  more  liberal.  In 
any  system  of  continuous  cropping,  or  in  fact  in  any  sys- 
tem of  rotation-cropping,  in  which  an  abundance  of 
organic  matter  is  introduced  in  the  way  of  green  crops, 
or  in  decaying  vegetable  matter  contained  in  roots,  the 


PLATE  XI.  —  Peppers  and  Red  Clover. 


FIG.  22.  —  PEPPERS   GROWN  UNDER  FIELD  CONDITIONS,   THOROFARB, 
NEW  JERSEY. 


FIG.  24.  —  EXCELLENT  SECOND  GROWTH  OF  RED  CLOVER  ON  HEAVILY 
FERTILIZED  POTATO  LAND,  FREEHOLD,  NEW  JERSEY. 


Fertilizers  for  Cereals  and  Grasses  235 

land  should  occasionally  receive  a  dressing  of  lime,  both 
to  supply  that  which  the  plants  need,  as  well  as  to  correct 
possible  acidity  of  soil. 

WILL  THIS  SYSTEM  OF  FERTILIZING  PAY? 

That  fertilization  will  pay  if  carried  out,  as  is 
pointed  out  here,  and  upon  lands  not  now  producing 
paying  crops,  depends,  of  course,  very  largely  upon 
the  price  of  the  crops,  the  cost  of  the  materials,  and 
the  method  of  farming  practiced.  At  the  prices 
which  have  prevailed  in  the  recent  past,  for  both 
crops  and  fertilizing  materials,  there  is  no  doubt 
that  this  reasonable  fertilization,  together  with  a  good 
system  of  practice  in  other  respects,  —  that  is,  good 
plowing,  good  harrowing,  good  drainage  and  good  culti- 
vation —  will  result  in  very  satisfactory  returns.  In 
fact,  it  has  been  shown  by  repeated  experiments  (see 
bulletins  and  reports  of  New  Jersey  Experiment 
Station)  that  the  yields  on  land  which  is  capable  of 
producing  an  average  crop  of  15  bushels  of  wheat  to 
the  acre,  30  of  corn  and  30  of  oats,  may  be  more 
than  doubled  by  an  abundant  supply  of  fertilizing 
materials.  Such  an  increase  results  in  an  actual  di- 
rect gain,  as  well  as  in  the  saving  of  labor  per  unit 
of  product,  which  is  accomplished  when  the  larger 
crop  is  secured. 

The  main  point  in  this  whole  matter  of  fertilization 
is  to  understand  that  a  fertilizer  is  a  fertilizer  because  of 
the  kind  and  form  of  plant-food  contained  in  it ;  and  that 
its  best  action,  other  things  being  equal,  is  accomplished 
when  the  soil  possesses  good  physical  qualities,  when  the 
management  is  also  good,  and  when  systematic  methods 


236  Fertilizers 

are  planned  and  adopted.  "Hit  or  miss"  fertilization, 
even  for  these  crops,  may  pay,  and  doubtless  on  the  aver- 
age does  pay  as  well  as  some  other  things  that  farmers  do, 
but  does  not  pay  as  well  as  it  might  if  better  methods  were 
used. 


CHAPTER  XIII 
FIELD   TRUCK  CROPS 

THE  truck  crops  differ  from  cereals  and  grasses  in  that 
they  are  products  of  high  commercial  value,  and  are  less 
exhaustive  of  plant-food  constituents,  that  is,  when  money 
value  is  made  the  unit  basis.  They  are  termed  "field 
truck  crops"  because  they  are  field  crops,  usually  grown 
in  rotation  and  form  a  special  crop  for  the  grower  which 
is  produced  solely  for  market  rather  than  for  manufacture 
upon  the  farm  into  a  farm  product.  In  sections  near  large 
markets  these  crops  are  divided  into  early  and  late,  the 
early  crop  being  regarded  as  the  more  profitable;  hence 
greater  efforts  are  made,  both  in  the  way  of  fertilization 
and  of  management,  to  secure  a  large  and  early  crop,  than 
is  the  case  with  the  late  crop.  For  the  early  crop  the  nat- 
ural supply  of  plant-food  in  the  soil  is  not  a  prune  consid- 
eration. In  districts  distant  from  markets,  the  late  crop 
is  the  only  one  grown  to  any  extent,  and  because  it  has  the 
whole  season  for  its  growth,  greater  dependence  is  placed 
upon  the  natural  resources  of  the  soil.  While,  as  already 
stated,  these  crops  are  not  regarded  as  exhaustive  of  plant- 
food  elements  in  the  same  sense  as  the  cereal  crops  are, 
because  it  frequently  happens  that  a  bushel  of  potatoes,  or 
of  sweet  potatoes,  or  of  tomatoes,  will  bring  as  much  as  a 
bushel  of  corn,  or  sometimes  as  a  bushel  of  wheat,  yet  the 
amount  removed  in  the  entire  crop  may  be  quite  as  great 
as  in  the  grain  crop,  because  of  the  much  larger  number 
of  bushels  grown  an  acre. 

237 


238  Fertilizers 


FERTILIZERS  FOR  POTATOES,  EARLY  CROP 

It  has  been  demonstrated,  both  by  experiment  and 
practical  experience,  that  good  crops  of  early  potatoes 
require  an  abundance  of  plant-food,  and  that  on  soils  of 
good  character  a  heavy  fertilization  is  usually  more  profit- 
able than  a  medium  or  light  application. 

The  plant-food  removed  by  a  fair  crop  —  200  bushels  to 
the  acre  of  tubers  —  will,  on  the  average,  consist  of  27 
pounds  of  nitrogen,  12  pounds  of  phosphoric  acid  and  60 
of  potash.  Even  though  the  increase  from  the  application 
of  fertilizers  is  less  than  100  bushels  to  the  acre,  it  is  always 
advisable  to  add  plant-food  in  considerable  excess  of  these 
amounts :  first,  because  the  crop  must  be  grown  quickly ; 
and  second,  because  a  large  part  of  its  growth  must  be 
made  in  the  early  season,  before  the  natural  conditions 
are  favorable  for  soil  activities.  A  study  of  the  fertility 
composition  of  the  potato  shows  that  of  the  three  essential 
constituents,  the  potash  is  contained  in  the  greatest 
amount  and  the  nitrogen  next,  while  the  amount  of  phos- 
phoric acid  contained  in  it  is  comparatively  small.  Most 
fertilizer  formulas  for  potatoes  are  therefore  prepared  with 
the  idea  of  furnishing  a  greater  amount  of  potash  than  of 
nitrogen  or  phosphoric  acid.  Studies  made  by  the  Geneva 
Experiment  Station  shows  that  the  formulas  prepared  to 
contain  the  plant-food  in  nearly  the  proportions  used  by 
the  entire  potato  plant,  excepting  that  the  phosphoric 
acid  is  in  considerable  excess,  were  less  useful  than 
those  containing  very  different  proportions  of  the  con- 
stituents, and  which  were  based  upon  the  experience 
of  observing  growers.  That  is,  a  formula  of  the  first 
class,  furnishing  — 


Field  Truck  Crops  239 


Nitrogen     ............ 

Available  phosphoric  acid      ......      5% 

Potash  .............     10% 

gave  less  satisfactory  returns  for  the  same  amount  applied 
than  one  furnishing  — 

Nitrogen    .....     .......      4% 

Available  phosphoric  acid      ......      8% 

Potash  .............     10% 

This  latter  formula  is  very  generally  used  in  sections 
where  early  potatoes  are  an  important  crop. 

The  time  and  method  of  application. 

These  are  matters  of  considerable  importance.  It 
has  been  urged,  particularly  by  German  experimenters, 
that  the  potash  salts,  when  used  in  such  excess  as  seems 
desirable,  should  be  applied  more  largely  to  the  crop 
preceding,  rather  than  directly  to  the  potato  crop.  This 
method  has  not  been  adopted  in  this  country  to  any  extent, 
and  it  is  believed  that  our  climatic  conditions  are  such  as 
to  cause  a  very  general  distribution  of  the  salts  throughout 
the  soil,  if  applied,  in  part  at  least,  just  before  planting 
and  thoroughly  distributed  by  cultivation.  At  any  rate, 
very  satisfactory  returns  are  secured  from  the  direct  ap- 
plication to  the  crop  of  fertilizers  of  this  composition.  In 
reference  to  the  method  of  application,  while  very  good 
results  are  secured  from  the  application  of  the  fertilizers 
directly  in  the  row,  this  is  to  some  extent  influenced  by  the 
character  of  the  soil.  Where  the  soil  is  somewhat  heavy, 
and  the  circulation  of  water  is  not  perfectly  free,  it  is  less 
desirable  than  where  the  soils  are  open  and  porous,  and 
free  circulation  is  not  impeded;  though  where  the 
amounts  applied  are  considerable,  it  is  recommended  that 


240  Fertilizers 

at  least  one-half  of  the  fertilizer  should  be  applied  broad- 
cast and  worked  into  the  soil,  and  the  remainder  placed  in 
the  row  at  the  time  of  planting.  Naturally,  when  the  soils 
are  poor,  a  concentration  of  the  constituents  is  more  de- 
sirable than  when  the  surrounding  soil  possesses  reasonably 
abundant  supplies  of  available  food. 

The  amount  to  be  applied.     (See  Fig.  18.) 

As  already  stated,  the  amount  of  the  different  constit- 
uents to  be  applied  should  be  in  considerable  excess  of 


FIG.  18.  —  THE  POTATO-PLANTER  WITH  FERTILIZER  ATTACHMENT, 

WHICH   DISTRIBUTES    FERTILIZER  EVENLY    IN   THE    ROW. 

that  required  by  the  actual  increase  in  crop,  both  for  the 
reasons  already  given,  and  because  it  is  desirable  in  crops 
of  this  sort  to  insure  a  continuous  and  abundant  feeding 
of  the  plant.  Where  "intensive"  practice  is  general, 
the  amounts  applied  very  frequently  reach  a  ton  to  the 
acre  of  the  high-grade  fertilizer  already  mentioned,  though 
the  necessity  for  so  large  an  application  as  this  has  been 
questioned,  particularly  if  it  is  expected  to  give  rise  to  a 
profitable  return  in  the  crop  to  which  the  application  is 


Field  Truck  Crops  241 

made,  and  though  it  can  be  readily  seen  that  if  conditions 
should  not  be  favorable,  the  larger  amounts  would  be  pref- 
erable. The  result  of  investigations  of  this  point  by  the 
Geneva  Experiment  Station  showed  that  an  addition  of 
fertilizers  above  1000  pounds  to  the  acre,  or  40  pounds  of 
nitrogen,  80  of  phosphoric  acid  and  100  of  potash,  was 
not  as  profitable  as  1000  pounds.  It  must  be  remembered, 
however,  that  these  experiments  were  conducted  upon  light 
soils,  and  on  these  entire  dependence  must  be  placed  upon 
added  plant-food. 

In  the  best  potato  sections  of  New  Jersey,  the  applica- 
tion of  a  fertilizer  of  this  composition  ranges  from  1000 
to  2000  pounds  to  the  acre,  while  the  larger  part  of  the 
growers  use  the  smaller  rather  than  the  greater  quantity. 
(See  Fig.  19,  Plate  IX.)  Many  use  the  larger,  and  are 
of  the  opinion  that  it  is  a  profitable  practice,  because  of 
the  greater  certainty  of  securing  a  good  potato  crop,  and 
because  the  unused  residue  provides  for  large  yields  of 
the  subsequent  crop  without  further  applications.  The 
growers  of  potatoes  in  the  vicinity  of  Norfolk,  as  well  as 
farther  south,  also  find  it  profitable  to  be  generous  in  the 
use  of  fertilizer  for  this  as  well  as  for  other  crops  of  high 
commercial  value. 

The  growers  of  Maine  use  the  larger  quantity  and  many 
are  now  gradually  changing  the  composition  of  the  fertilizer 
applied  by  increasing  the  nitrogen  to  5  per  cent  and  de- 
creasing the  potash  to  7  per  cent.  It  is  not  uncommon  in 
Maine  to  make  two  applications  during  a  season.  This 
method  has  become  known  as  the  Aroostook  County 
method.  In  some  cases  the  fertilizer  is  merely  divided 
into  two  parts  and  put  on  at  intervals  of  three  weeks  or  a 
month,  but  in  other  cases  the  first  application  made  at  the 
time  of  planting  contains  only  organic  nitrogen,  whereas 


242  Fertilizers 

the  second  application  contains  nitrogen  drawn  from  sol- 
uble sources.  The  second  application  is  made  when  the 
vines  are  three  or  four  inches  high  and  the  fertilizer  is 
dropped  right  on  them  and  then  the  entire  plant  is  covered 
with  soil.  When  this  method  is  practiced,  it  is  believed 
that  more  efficient  use  is  made  of  the  nitrogen,  and  that 
the  vines  have  ample  opportunity  for  increased  root 
development.  While  this  method  is  successful  in  Maine, 
it  has  not  proved  to  be  superior  in  New  Jersey  and  warmer 
climates.  It  is  applicable  to  both  early  and  late  potatoes. 

Form  of  the  constituents. 

In  the  growing  of  potatoes,  sulfate  of  potash  is  generally 
recommended  in  preference  to  the  muriate,  owing  to  the 
supposedly  deleterious  effect  on  the  quality  of  the  tubers 
resulting  from  the  large  quantities  of  chlorids  contained 
in  the  muriate,  though  the  different  forms,  when  properly 
applied,  do  not  seem  to  materially  influence  the  yield. 
That  is,  if  muriate  or  kainit  is  applied  previous  to  the 
planting  of  potatoes,  the  deleterious  chlorids  derived  from 
the  muriate  may  be  washed  from  the  soil.  There  is  no 
doubt  that  the  sulfate  improves  the  appearance  of  the  pota- 
toes, making  them  more  clean  and  uniform  in  size,  though 
experiments  that  have  been  conducted  do  not  show  a 
material  difference  in  the  chemical  composition  of  the 
tubers  grown  with  any  of  the  forms.  The  tendency  on 
the  part  of  the  muriate  seems  to  be  to  diminish  the  amount 
of  dry  matter,  and  inasmuch  as  the  dry  matter  is  mostly 
starch,  the  latter  is  thereby  slightly  reduced,  though  it 
has  not  yet  been  demonstrated  that  the  good  quality  of 
the  potatoes  is  measured  by  the  content  of  starch.1 

1  Bulletin  No.  137,  N.  Y.  State  (Geneva)  Exp.  Sta. ;  Bulletin 
No.  80,  N.  J.  Exp.  Sta. 


Field  Truck  Crops  243 

In  reference  to  the  form  of  nitrogen,  both  theoretical 
considerations  and  the  experience  of  growers  confirm 
the  belief  that  for  the  early  crop  a  portion  of  the  nitrogen 
should  exist  in  the  form  of  nitrate  or  ammonia  and  the 
remainder  in  quickly  available  organic  forms,  although  no 
definite  experiments  have  been  conducted  to  determine 
this  point,  nor  the  one  as  to  whether  all  of  the  nitrogen  in 
the  form  of  nitrate  should  be  applied  at  the  time  of  plant- 
ing. A  top-dressing  after  the  potatoes  have  come  up  is  a 
very  desirable  method  of  practice  on  light  soils  which 
have  been  liberally  supplied  with  the  minerals. 

On  good  potato  soils,  therefore,  a  good  fertilization  would 
consist  of  1000  pounds  to  the  acre,  as  a  minimum,  of  a 
mixture  containing : 

Nitrogen 4% 

Phosphoric  acid 8% 

Potash 8% 

The  nitrogen  is  to  be  in  quickly  available  forms;  the 
phosphoric  acid,  also,  is  to  be  available,  and  the  potash  to 
be  derived  from  sulfate,  particularly  if  fine  quality  of  crop, 
as  indicated  by  appearance,  is  desired.  If  only  yield  is 
considered,  the  muriate  is  quite  as  serviceable. 

LATE  POTATOES 

For  late  potatoes,  the  considerations  in  reference  to  the 
form  of  the  constituents  and  the  amount  of  the  application, 
as  suggested  for  early  potatoes,  do  not  always  hold  good, 
since  in  many  cases  the  crop  is  able  to  secure  a  larger  pro- 
portion of  its  plant-food  from  soil  sources,  —  due,  first, 
to  the  longer  period  of  growth  of  the  plant,  and  second,  to 
the  fact  that  the  crop  is  usually  grown  upon  soils  naturally 


244  Fertilizers 

richer  in  the  plant-food  elements,  though  the  proportion 
of  potash,  as  in  the  formulas  already  indicated,  should 
be  relatively  large.  The  nitrogen  may  be  reduced,  and 
the  form  of  nitrogen  may  be  derived  largely  from  quickly 
available  organic  sources.  Good  formulas  for  late  po- 
tatoes may  consist  of  — 

Nitrogen 3% 

Phosphoric  acid 6% 

Potash 8% 

and  the  application  may  be  from  800  to  1200  pounds  to 
the  acre. 

Where  potatoes  are  grown  in  rotations  with  the  cereal 
crops  mentioned  in  Chapter  XII,  the  unused  residue  from 
the  rather  heavy  application  of  fertilizers  to  the  potato 
crop  is  depended  upon  to  aid  very  materially  the  growth  of 
these,  thus  reducing  the  outlay  for  fertilizer  for  crops  of 
a  low  commercial  value.  This  practice  is  advantageous, 
though  the  prime  object  should  be  to  feed  the  crop  rather 
than  the  soil  —  that  is,  apply  the  fertilizer  with  the  idea  of 
securing  a  profit  from  it  in  the  potato  crop,  rather  than  a 
possible  profit  in  subsequent  crops. 

SWEET  POTATOES 

In  the  growing  of  sweet  potatoes,  the  quality  of  the  prod- 
uct is  more  important  than  in  the  case  of  the  white  potato. 
The  northern  markets  distinctly  recognize  quality  in  this 
crop,  and  it  is  measured  by  size,  shape  and  results  in  cook- 
ing. The  potato  that  brings  the  best  price  in  the  different 
markets  is  small,  about  the  size  of  a  white  potato;  in 
shape  round,  rather  than  oblong,  and  is  dry  and  mealy 
when  cooked.  This  characteristic  of  the  crop  is  influenced 


Field  Truck  Crops  245 

both  by  the  character  of  the  soil  and  of  the  manures  and 
fertilizers  applied.  The  soils  best  adapted  are  dry,  sandy 
loams,  and  the  most  useful  fertilizers  are  those  which 
contain  an  abundance  of  minerals  —  phosphoric  acid 
and  potash  —  and  not  too  large  supplies  of  quickly  avail- 
able nitrogen.  It  is  also  true  that  the  yields  of  sweet  po- 
tatoes of  this  character  are  not  as  large  as  those  that  may 
be  obtained  when  quality  is  not  a  prime  consideration,  and 
which  are  grown  for  the  general  market. 

Fertilizer  constituents  contained  in  an  average  crop. 

This  crop  is  very  similar  to  the  white  potato  in  regard 
to  food  required.  Two  hundred  bushels  of  sweet  pota- 
toes, not  including  vines,  contain,  on  the  average,  30 
pounds  of  nitrogen,  10  of  phosphoric  acid  and  45  of  potash ; 
and  since  the  yield  of  the  general  crop  is  larger  on  the  aver- 
age than  one  of  white  potatoes,  a  liberal  supply  of  the 
minerals  must  in  all  cases  be  provided.  The  studies  made 
of  this  crop  have  not  yet  established  the  best  proportions 
of  the  constituents  in  fertilizers,  though  such  experiments 
as  have  been  conducted  show  that  those  that  contain  a 
very  considerable  excess  of  potash  over  the  other  elements 
are  preferable.  While  nitrogen  is  needed,  too  much, 
particularly  in  soluble  forms,  seems  to  encourage  too  large 
a  growth  of  vine,  which  contributes  to  yield,  but  at  the 
expense  of  quality,  which  is  a  very  important  considera- 
tion. The  best  growers  use  fertilizers  containing  a  small 
percentage  of  nitrogen  and  a  high  percentage  of  phosphoric 
acid  and  potash.  Applications  that  furnish  20  pounds  of 
nitrogen,  50  of  phosphoric  acid  and  80  of  potash  to  the 
acre  have  given  excellent  results  in  regions  in  New  Jersey 
in  which  market  quality  up  to  a  certain  point  is  quite  as 
important  as  increase  in  yield,  though,  of  course,  yield 


246  Fertilizers 

is  also  considered.  Any  excess  of  nitrogen  over  this 
amount  seems  to  contribute  toward  a  larger,  rather  oblong, 
rooty  growth  of  tuber,  and  to  injure  cooking  quality.  In 
growing  crops  for  the  general  market,  however,  larger 
applications  of  nitrogen  are  demanded,  and  experiments 
have  shown  that  organic  forms  are  preferable  to  soluble 
forms,  though  the  climate  and  season  largely  influence 
this  point.  In  northern  sections,  and  in  cold  seasons,  the 
soluble  forms  are  more  useful  than  in  the  warmer  climate 
and  longer  seasons  of  the  South. 

There  is  no  question,  however,  that  commercial  fer- 
tilizers can  be  depended  upon  to  produce  maximum  crops 
of  sweet  potatoes,  and  at  much  smaller  cost  than  with 
yard  manure.1  Results  reported  by  the  Georgia  Ex- 
periment Station2  indicate  the  following  formula  as  an 
excellent  one  for  sweet  potatoes,  though,  as  there  stated, 
"  the  amounts  that  can  be  used  vary  considerably,  depend- 
ing upon  the  character  of  the  soil  —  the  richer  the  land  in 
humus,  the  greater  the  quantity  that  can  be  safely  used." 
"  Thin  soils  will,  of  course,  only  stand  very  moderate  ma- 
nuring, and  necessarily  produce  a  very  small  yield."  The 
formula  consists  of  — 

Acid  phosphate 320  Ibs. 

Cotton-seed  meal 360  Ibs. 

Kainit 640  Ibs. 

This  formula  will  furnish  about  25  pounds  of  nitrogen, 
50  of  phosphoric  acid  and  80  of  potash,  and,  according  to 
the  bulletin,  will  produce  a  yield  of  potatoes  from  200  to 
400  bushels  to  the  acre,  depending  upon  the  season  and 
variety  of  potatoes  planted.  Experiments  at  the  Georgia 

1  Bulletin  P,  New  Jersey  Exp.  Sta. 

2  Bulletin  No.  25,  Georgia  Exp.  Sta. 


Field  Truck  Crops  247 

Station  also  show  that  organic  nitrogen  (cotton-seed  meal) 
is  preferable  to  nitrate  of  soda  as  a  source  of  nitrogen. 

In  making  mixtures  which  furnish  these  proportions  of 
plant-food,  other  nitrogenous  organic  materials  furnishing 
an  equivalent  of  nitrogen  —  as  blood  or  concentrated 
tankage  —  may  be  substituted  for  the  cotton-seed  meal, 
if  they  can  be  purchased  quite  as  cheaply ;  and  muriate 
of  potash,  furnishing  an  equivalent  of  potash,  may  be  sub- 
stituted for  the  kainit,  if  it  can  be  more  readily  obtained. 

As  already  stated,  however,  this  fertilizer  is  too  rich  in 
nitrogen  for  the  production  of  the  best  quality  of  potatoes, 
as,  for  example,  "Vineland  Sweets/'  which  command  the 
highest  prices  in  northern  markets.  The  growers  in 
that  district  use  a  fertilizer  richer  in  the  minerals;  one 
containing  — 

Nitrogen 3% 

Phosphoric  acid 7% 

Potash 12% 

is  very  generally  used,  though  reasonably  heavy  dressings 
of  this  are  often  further  supplemented  by  applications  of 
from  200  to  300  pounds  of  acid  phosphate  and  100  to  150 
pounds  of  muriate  of  potash  to  the  acre. 

The  application  of  the  fertilizers. 

Owing  to  the  fact  that  the  sweet  potato  is  grown  from 
plants  or  slips,  rather  than  from  seed,  and  the  fact  that  the 
best  quality  of  potatoes  is  produced  upon  rather  light, 
sandy  land,  it  is  desirable  that  the  fertilizer  should  be 
applied  some  time  before  the  putting  out  of  the  plants. 
The  practice  on  this  light  land  is  to  apply  the  fertilizer 
when  making  up  the  hills,  which  usually  occurs  from  two  to 
three  weeks  before  the  plants  are  set.  That  is,  in  making 


248  Fertilizers 

up  the  hills,  the  soil  is  ridged,  and  during  the  preparation 
of  the  ridge  the  fertilizer  may  be  distributed  in  it  and  well 
mixed  with  the  soil.  Where  the  land  contains  more  clay 
and  humus  it  is  frequently  advocated  that  the  potash 
manures  be  applied  broadcast  the  previous  year,  and  only 
the  nitrogenous  fertilizer  and  superphosphate  be  applied 
immediately  to  the  plant.  On  soils  of  this  latter  char- 
acter, this  is  doubtless  the  best  system.  If  kainit  — 
which  has  been  found  to  be  preferable  to  muriate  in  the 
Georgia  experiments  referred  to  —  is  used  as  the  source  of 
potash,  it  is  very  necessary  that  it  be  well  mixed  with  the 
soil  before  setting  out  the  plants.  Heavy  applications  of 
this  salt  in  the  spring  proved  injurious  in  the  experiments 
conducted  at  the  New  Jersey  Station.  The  effect  of 
fertilizers  upon  the  chemical  composition  of  the  tuber  was 
chiefly  to  reduce  dry  matter,  and  not  apparently  to  affect 
edible  quality,  though  the  experiments  were  carried  out 
upon  the  general  crop  rather  than  upon  those  grown  for 
high  quality. 

TOMATOES 

Tomatoes  are  largely  grown  as  a  field  crop,  and  the  ob- 
ject of  their  growth,  whether  for  the  early  market  or  for 
the  canneries,  is  a  factor  that  must  be  considered  in  the 
adoption  of  systems  of  fertilization. 

Field  experiments  with  fertilizers  for  tomatoes. 

The  impression  is  very  prevalent  among  growers  that 
the  tomato  does  not  require  heavy  manuring.  Studies 
made  at  a  number  of  experiment  stations  show,  however, 
that  the  tomato  is  a  plant  that  quickly  and  profitably 
responds  to  the  use  of  manures  or  fertilizers,  and  that  the 
maturity  and  yield  are  very  largely  influenced  by  the 


Field  Truck  Crops  249 

method  of  manuring  and  fertilizing.  Experiments  were 
conducted  by  the  New  Jersey  Station  upon  three  farms 
located  in  different  parts  of  the  state,  and  during  four  sea- 
sons, the  object  of  which  was  to  test  the  effect  on  maturity 
and  yield  of  the  early  crop  of  the  use  of  nitrate  of  soda  in 
different  quantities  and  at  different  times,  both  with  and 
without  the  addition  of  the  mineral  elements,  phosphoric 
acid  and  potash,  and  to  make  a  comparison  of  these  with 
barnyard  manure.  The  results  showed : 

1.  That  nitrate  of  soda  was  one  of  the  best  nitrogenous 
fertilizers  for  this  crop,  and  that  its  use  in  small  quantities 
(160  pounds  to  the  acre),  or  in  large  quantities  (320  pounds 
to  the  acre)  in  two  applications,  increased  the  yield  ma- 
terially, but  not  at  the  expense  of  maturity,  and  that  this 
was  equally  true  when  used  alone  and  when  used  in  con- 
nection with  phosphoric  acid  and  potash. 

2.  That  nitrate  of  soda,  when  used  in  large  quantities 
(320  pounds  to  the  acre)  in  one  application,  in  the  presence 
of  a  sufficient  excess  of  phosphoric  acid  and  potash,  did 
increase  the  yield,  but  at  the  expense  of  maturity. 

3.  That  when  properly  used,  nitrate  of  soda  was  a 
profitable  fertilizer  for  the  crop. 

It  was  shown,  furthermore,  that  nitrate  of  soda  was 
superior  to  both  barnyard  manure  and  mineral  fertilizers 
alone,  and  on  the  whole,  was  but  slightly  less  effective 
than  the  complete  fertilizers. 

Fertilizers  for  the  early  crop  for  different  conditions  of  soil. 

These  results  have  been  practically  confirmed  both  by 
the  experiments  of  the  stations  referred  to,  and  also  in 
actual  practice  on  soils  similar  in  character;  namely, 
those  which  were  well  adapted  for  the  early  tomato  — 
light,  well-drained  sandy  loams  (see  Fig.  20,  Plate  X) 


250  Fertilizers 

—  and  which  had  been  previously  well  manured  for  crops 
entering  the  rotation.  The  results  do  not  apply  in  the 
case  of  very  poor  soils,  or  upon  heavy  clay  soils,  which 
are  not  adapted  for  the  early  crop. 

The  statement  that  it  pays  to  fertilize  early  tomatoes, 
and  that  nitrate  of  soda  is  one  of  the  best  fertilizers  for 
the  crop,  must  therefore  be  accompanied  by  statements 
regarding  the  condition  of  soil  and  the  purpose  of  growth. 
With  the  conditions  clearly  understood,  a  scheme  of 
fertilization  for  early  tomatoes  may  be  outlined  which, 
when  the  conditions  are  observed,  will  be  likely  to  give 
much  better  results  than  methods  of  fertilization  which  do 
not  take  into  consideration  the  habits  of  the  plant  and  the 
special  object  of  its  growth. 

For  example,  on  soils  which  have  been  well  supplied 
with  phosphoric  acid  and  potash  by  manuring  and  fertiliz- 
ing previous  to  setting,  a  complete  fertilizer  containing 
sufficient  nitrogen  derived  from  nitrate  of  soda  to  start 
the  plant  nicely  should  be  used.  If  as  much  as  80  pounds 
of  phosphoric  acid  and  100  pounds  of  potash  have  been 
supplied,  an  application  of  100  to  150  pounds  of  nitrate  of 
soda  alone  may  be  used,  followed  by  a  side-dressing  of 
150  to  200  pounds  of  nitrate  of  soda  after  the  fruit  has 
set  and  grown  to  about  the  size  of  walnuts.  Care  should 
be  exercised  not  to  make  the  application  at  the  time  of 
setting  too  large,  because  too  rank  growth  often  causes  the 
plants  to  shed  their  bloom.  A  single  application  at  the 
time  of  setting  the  plants  would,  perhaps,  under  good 
seasonal  conditions  give  results  quite  as  good,  though 
the  heavier  application  of  nitrate  at  one  time  may  result, 
in  certain  cases,  in  the  loss  of  nitrogen  by  leaching,  since  it 
is  an  extremely  soluble  salt.  In  this  case  a  deficiency  of 
food  would  result,  and  thus  prevent  normal  development. 


Field  Truck  Crops  251 

On  soils  which  possess  only  good  mechanical  condition, 
and  are  very  poor  in  plant-food,  a  heavier  application  of 
both  nitrogen  and  the  mineral  elements  will  be  required, 
in  which  case  the  following  fertilization  is  recommended : 

Previous  to  setting  the  plants,  or  at  the  time  they  are 
set,  apply  75  pounds  to  the  acre  of  phosphoric  acid,  pref- 
erably derived  from  superphosphate,  and  100  pounds  of 
potash,  derived  from  muriate,  and  thoroughly  harrow  or 
cultivate  into  the  soil ;  and  at  the  time  of  setting  apply 
around  the  hill  100  to  150  pounds  to  the  acre  of  nitrate  of 
soda.  Three  to  four  weeks  later,  make  another  application 
of  from  100  to  150  pounds  to  the  acre  of  nitrate  of  soda. 
Owing  to  the  small  bulk  of  nitrate,  it  should  be  mixed  with 
dry  soil  or  sawdust,  in  order  to  insure  even  distribution. 
The  only  precaution  to  be  observed  is  to  prevent  its  im- 
mediate contact  with  the  plant  roots.  If  these  methods 
are  practiced,  the  plant  secures  its  nitrogen  in  an  im- 
mediately available  form  at  a  time  when  it  is  needed,  — 
when  it  is  set  in  the  field.  There  is  thus  no  delay  in  growth, 
and  because  of  the  presence  of  an  abundance  of  the  mineral 
elements,  no  excessive  growth  of  vine  is  encouraged  by  the 
use  of  the  nitrate,  as  would  be  the  case  were  the  mineral 
elements  absent.  Inasmuch  as  the  nitrogen  is  applied 
close  to  the  plant,  it  is  within  the  immediate  reach  of  its 
roots;  and  because  it  is  all  in  an  immediately  available 
form,  which  is  used  up  rapidly,  the  tendency  to  late  plant 
growth,  which  would  be  caused  by  a  continuous  supply 
of  nitrogen,  is  not  encouraged,  and  a  normal  and  rapid 
growth  and  development  of  fruit  results. 

It  is  not  stated  that  by  this  method  of  fertilization 
maturity  is  increased  in  the  sense  that  the  date  of  the  first 
picking  is  earlier,  but  that  a  larger  number  of  fruits  is 
picked  earlier.  It  was  not  shown  in  any  of  the  experiments 


252  Fertilizers 

that  the  date  of  picking  was  made  earlier  by  virtue  of  the 
nitrate,  for,  in  fact,  the  earliest  tomatoes  were  picked  upon 
land  where  the  minerals  only  had  been  applied.  Here  the 
yield  was  not  satisfactory,  but  where  the  nitrate  was 
applied,  because  of  the  larger  crop,  a  larger  proportion  of 
early  tomatoes  was  secured.  It  is  obvious  that,  inasmuch 
as  the  price  of  the  fruit  rapidly  declines  as  the  season  ad- 
vances, receipts  from  the  proportionately  larger  quantity 
of  early  fruit  will  be  materially  increased. 

The  use  of  fertilizers  with  yard  manures. 

When  it  is  desirable  to  use  yard  manures  with  fertilizers 
for  tomatoes,  because  of  the  abundance  and  cheapness 
of  the  former,  they  should  be  applied  broadcast,  and  the 
nitrate  applied  at  the  time  of  planting,  as  already  described, 
rather  than  both  together  in  the  hill.  The  tendency  in 
the  latter  case  will  be  to  cause  a  loss  of  nitrogen  from  the 
nitrate,  depending  upon  the  amount  of  organic  matter 
in  the  manures.  That  is,  experiments  and  experience 
have  shown  that  under  these  circumstances  more  or  less 
of  the  nitrogen  in  the  nitrate  may  be  lost. 

In  the  use  of  yard  manures  for  early  tomatoes,  the  ap- 
plication of  excessive  quantities  should  be  avoided,  as 
they  are  virtually  nitrogenous  manures,  which,  because 
of  their  organic  character,  feed  the  plant  in  proportion 
to  their  rate  of  decay.  Hence,  the  presence  of  large  quan- 
tities will  encourage  not  only  an  undue  growth  of  plant, 
but  a  late  growth  as  well.  The  mineral  fertilizers,  as 
acid  phosphate  and  muriate  of  potash,  can  be  used  with 
the  yard  manures  with  perfect  safety,  in  fact,  with  great 
advantage,  because  they  supplement  the  proportionate 
lack  of  mineral  constituents.  It  is  also  desirable,  where 
it  is  the  practice  to  use  manure,  particularly  if  it  is  coarse, 


Field  Truck  Crops  253 

to  spread  it  during  the  winter,  in  order  that  the  soluble 
portions  may  become  thoroughly  distributed  throughout 
the  soil.  As  soon  as  the  land  is  ready  to  work  in  the  spring, 
it  should  again  be  plowed  shallow  and  then  deeply  tilled, 
in  order  both  to  thoroughly  warm  up  the  soil,  and  to  in- 
corporate with  it  coarser  portions  of  the  manure. 

Upon  light,  sandy  soils  coarse  manure  may  be  used, 
provided  it  is  spread  broadcast  some  time  before  working 
the  soil;  whereas,  upon  heavy,  cold  soils,  well-rotted 
manure  should  be  used  and  its  application  confined  to 
the  hill. 

Fertilizers  for  late  tomatoes. 

In  manuring  and  fertilizing  for  the  late  crop,  the  charac- 
ter of  the  crop  and  the  season  of  its  growth  should  be 
remembered.  In  the  first  place,  the  plants  for  this  crop 
are  not  put  in  the  soil  until  summer,  when  the  conditions 
are  most  favorable  for  the  rapid  change  of  organic  forms 
of  nitrogen  into  nitrates.  Thus,  if  the  soil  has  been 
manured  or  is  naturally  rich  in  vegetable  matter,  the  ad- 
ditional application  of  nitrogen  in  immediately  available 
forms  is  not  so  important.  In  the  second  place,  the  object 
of  the  growth  is  not  early  maturity,  but  the  largest  yield  of 
matured  fruit ;  hence  it  is  more  desirable  to  grow  a  larger 
plant  than  in  the  case  of  the  early  tomatoes.  The  fer- 
tilization should  therefore  be  such  as  to  furnish  an  abun- 
dance of  all  the  elements  of  plant-food ;  and,  inasmuch  as 
the  tomato  belongs  to  the  potash-consuming  class  of 
plants,  any  fertilization  should  be  particularly  rich  in  this 
element.  It  is  not  to  be  understood,  however,  that  it 
is  not  necessary  to  apply  nitrogen,  for  frequently  soils 
are  used  that  are  either  not  well  adapted  for  the  plant 
or  are  poor,  not  having  been  previously  well  supplied 


254 


Fertilizers 


with  vegetable  matter  containing  nitrogen.  On  such 
soils,  additional  applications  are  very  important,  and 
nitrate  of  soda  is  one  of  the  best  forms  to  use,  as  it  is  ab- 
sorbed freely  by  the  roots,  encouraging  an  early  and  vigor- 
ous growth  of  plant  and  a  normal  development  of  fruit. 
Slow-acting  organic  forms  of  nitrogen,  on  the  other  hand, 
frequently  begin  to  feed  the  plant  and  cause  its  rapid 
growth  when  the  energies  should  be  concentrated  in  the 
growth  and  maturity  of  fruit.  Fertilizers  that  have  proved 
very  excellent  are  those  which  contain  a  relatively  smaller 
amount  of  nitrogen  than  is  required  for  early  tomatoes, 
and  are  richer  in  phosphoric  acid  and  potash. 

A  study  of  the  composition  of  both  the  fruit  and  vine 
of  the  tomato  will  serve  to  guide  us  in  this  respect,  though 
the  amounts  and  proportions  of  food  removed  by  any  crop 
are  not  absolute  guides,  inasmuch  as  the  soil  may  furnish 
more  of  one  constituent  than  another,  and  because  the 
plant  may  have  the  power  of  acquiring  certain  of  its  con- 
stituents more  readily  than  others.  The  analyses  of  the 
fruit  and  vines  of  tomatoes  show  that  one  ton  contains: 


NlTKOGEN,  LBS. 

PHOSPHORIC 
ACID,  LBS. 

POTASH,  LBS. 

In  fruit      

3.20 

1.00 

5.40 

Vines  (green)      .... 

6.40 

1.40 

10.00 

Ten  tons  of  the  fruit,  with  the  accompanying  vines, 
which  would  probably  reach  four  tons,  would  contain 
57  pounds  of  nitrogen,  16  of  phosphoric  acid  and  94  of 
potash.  On  a  good  soil,  therefore,  which  without  manure 
would  produce  five  or  six  tons,  there  should  be  added  a 
sufficient  excess  of  the  constituents  to  provide  for  a  maxi- 
mum production,  and  the  materials  should  be  relatively 


Field  Truck  Crops  255 

richer  in  nitrogen  and  potash  than  in  phosphoric  acid.  A 
mixed  fertilizer  composed  of  : 

Nitrate  of  soda 300  Ibs. 

Bone  tankage 500  Ibs. 

Acid  phosphate 800  Ibs. 

Muriate  of  potash 400  Ibs. 

would  contain,  approximately,  75  pounds  of  nitrogen, 
156  of  phosphoric  acid  and  200  of  potash  in  each  ton. 
An  application  of  1000  pounds  to  the  acre  of  this  mixture 
would  furnish  nearly  half  as  much  nitrogen  as  is  contained 
in  a  crop  of  ten  tons,  a  surplus  of  phosphoric  acid,  and  an 
equal  amount  of  potash.  Hence  a  dressing  containing  the 
amounts,  kinds  and  proportions  of  plant-food  here  shown 
would  be  regarded  as  very  desirable,  since  one-half  of 
the  nitrogen  is  in  the  form  of  a  nitrate,  which  would  con- 
tribute to  the  immediate  growth  of  the  plant.  The 
amount  of  soluble  and  available  phosphoric  acid  is  suffi- 
cient to  satisfy  the  needs  of  the  crop  throughout  its  entire 
growth,  and  such  an  abundance  of  potash  as  to  contribute 
to  the  normal  development  of  both  plant  and  fruit.  For- 
mulas of  this  character  have  been  used  with  good  results, 
though  the  large  proportion  of  salts  sometimes  make 
mixtures  of  this  sort  too  moist  to  handle  well,  in  which 
case  a  part  of  the  potash,  or  even  of  the  nitrate,  may  be 
applied  separately  with  advantage.  On  poorer  soils, 
the  artificial  supply  of  plant-food  should  be  proportionately 
greater,  or  sufficient  to  provide  for  the  entire  needs  of  a 
fair-sized  crop,  since  as  a  rule  the  relative  power  of  the 
plant  to  acquire  food  is  somewhat  slighter  on  poor  soils 
than  on  good  soils ;  or,  stated  in  another  way,  the  results 
from  the  use  of  fertilizers  are  proportionately  better  upon 
soils  in  good  condition  than  upon  those  not  well  cared  for. 
A  good  formula  for  these  may  consist  of : 


256  Fertilizers 

Nitrate  of  soda 500  Ibs. 

Bone  tankage 500  Ibs. 

Acid  phosphate 400  Ibs. 

Muriate  of  potash 600  Ibs. 

One  ton  of  this  mixture  would  furnish,  approximately, 
105  pounds  of  nitrogen,  120  of  phosphoric  acid  and 
300  of  potash.  The  application  of  1000  pounds,  there- 
fore, would  furnish  the  food  in  sufficient  abundance  and 
in  good  proportions  to  meet  the  demands  of  a  fair  crop. 
There  is  a  contention  prevalent  among  large  growers  of 
late  tomatoes  that  ammonium  sulfate  as  a  source  of  nitro- 
gen causes  injury,  and  it  is  thought  best  to  omit  it  even 
though  there  are  not  reliable  experiments  to  prove  this 
contention. 

The  advantage  of  using  so  large  a  proportion  of  nitrogen 
in  the  form  of  nitrate  of  soda  in  this  case  is,  that  it  is  im- 
mediately available,  inducing  the  immediate  and  rapid 
growth  of  plant,  and  preventing  a  too  late  growth  by 
furnishing  a  minimum  of  organic  nitrogen,  which  would 
become  available  late  in  the  season.  The  cost  of  the 
fertilizer  suggested  in  these  cases  is  high,  and  the  necessity 
of  so  expensive  a  dressing  could  be  materially  reduced 
by  decreasing  the  need  for  nitrogen,  particularly  in  organic 
forms,  which  may  be  accomplished  by  showing  crimson 
clover  with  or  after  the  previous  crop  of,  say,  corn  or 
tomatoes.  If  weather  conditions  are  favorable,  crimson 
clover  may  be  sown  in  the  tomato  fields  in  August,  after 
cultivation  has  ceased,  or  at  the  last  cultivation,  and  a 
crop  of  clover  grown  which  will  provide  nitrogen  for  the 
next  year's  crop.  This  method  is  now  practiced  with 
advantage  by  many  growers.  The  late  crop,  like  potatoes 
and  sweet  potatoes,  is  usually  grown  in  rotations  in  which 
it  is  the  chief  money  crop ;  hence  the  unused  residue  from 


Field  Truck  Crops  257 

fertilizers  applied  in  large  amounts,  as  here  indicated, 
contributes  largely  to  the  economical  growth  of  subsequent 
crops.  (See  Fig.  21,  Plate  X.) 

PEPPERS  AND  EGGPLANT.     (See  Fig.  22,  Plate  XI.) 

It  is  not  an  uncommon  practice  to  grow  peppers  and 
eggplant  as  a  special  crop  under  field  conditions  upon 
small  farms,  and  often  these  plants  may  be  seen  occupying 
the  same  field.  With  these  plants  it  is  important  that 
a  liberal  supply  of  quickly  available  nitrogen  be  supplied 
early  in  the  growing  season  to  produce  early  growth  and 
strong  foliage,  although  an  excess  should  be  avoided.  It 
is  a  good  practice  to  derive  one-half  of  the  nitrogen  from 
quickly  available  organic  materials.  Before  transplanting, 
the  soil  should  receive  not  less  than  1000  pounds  of  a 
mixture  composed  of 

Nitrate  of  soda 200  Ibs. 

Dried  blood,  16%  am 150  Ibs. 

Dried  fish 150  Ibs. 

Acid  phosphate 1100  Ibs. 

Muriate  of  potash 400  Ibs. 

As  soon  as  the  plants  are  well  established,  a  side-dressing 
of  nitrate  of  soda  should  be  used  and  immediately  worked 
into  the  soil.  This  practice  may  be  repeated  twice  or 
three  times  and  the  amounts  to  apply  fixed  accordingly. 
Upon  light  soils  well-rotted  yard  manure  may  be  used 
advantageously,  especially  when  well  worked  into  the 
soil. 

PEAS  AND  BEANS 

In  canning  sections,  peas  are  grown  upon  large  acreages 
and  followed  by  bush  beans.  It  is  often  the  practice  to 


258  Fertilizers 

grow  them  year  after  year  upon  the  same  soil,  and  under 
such  conditions  it  is  necessary  to  give  special  attention 
to  the  fertilization.  Because  both  crops  are  legumes,  little 
nitrogen  is  needed  except  during  the  early  stages  of 
growth  to  start  the  plants  well.  For  peas  the  nitrogen 
should  be  derived  largely  from  available  sources,  75 
pounds  of  nitrate  of  soda,  400  of  acid  phosphate  and  100 
of  muriate  of  potash  should  supply  the  needed  plant-food. 
The  beans  which  follow  should  thrive  upon  the  residual 
fertility  elements,  but  it  is  often  well  to  make  an  additional 
application  of  400  or  500  pounds  of  a  mixture  high  in  the 
mineral  elements  and  deriving  its  nitrogen  almost  entirely 
from  organic  sources  to  prolong  the  period  of  growth. 
It  should  be  remembered  that  these  crops  thrive  best  upon 
soils  rich  in  organic  matter,  and  it  is  a  good  plan  to  return 
the  vines  to  the  soil. 

FIELD  BEANS 

Field  beans,  often  called  white  beans,  are  grown  ex- 
tensively for  the  food-stuffs  market.  This  crop  should 
be  given  different  treatment  than  the  garden  bean  because 
it  is  grown  for  the  mature  seed  and  the  growing  period  is 
much  longer.  When  grown  in  a  rotation  of  beans,  wheat 
and  clover,  little  nitrogen  need  be  used.  When  corn  is 
included  in  the  rotation,  more  nitrogen  should  be  applied. 
In  general,  no  less  than  400  pounds  of  a  mixture  com- 
posed of 

Nitrate  of  soda 200  Ibs. 

Dried  blood 100  Ibs. 

Acid  phosphate 1300  Ibs. 

Muriate  of  potash      ..-    '*.' 400  Ibs. 

should  be  used  to  the  acre. 


Field  Truck  Crops  259 

GENERAL  CONSIDERATIONS 

The  foregoing  crops  differ  materially  from  one  another  in 
many  respects,  though  they  are  all  heavy  potash  feeders. 
They  are  considered  here  primarily  as  special  crops  pro- 
duced upon  general  or  dairy  farms ;  hence,  it  must  be 
remembered  that  there  are  numerous  factors  which  in- 
fluence the  fertilization,  chief  among  which  are :  the  kind 
of  soil,  the  rotation  and  system  of  fertilization  and  the 
length  of  growing  season  required  by  each. 


CHAPTER  XIV 
GREEN  FORAGE  CROPS 

A  LARGE  number  of  crops  is  included  in  this  class. 
In  dairy  districts  they  are  grown  for  summer  feeding, 
mainly  to  supplement  or  to  substitute  pasturage  entirely, 
as  well  as  to  provide  a  succulent  ration  of  roughage  in 
winter.  Any  crop  which  grows  quickly,  is  palatable 
and  makes  a  reasonably  large  yield,  is  adapted  for  the 
purpose.  For  convenience  of  study,  these  crops  may  be 
further  classified  into  four  groups  :  1.  cereals  and  grasses ; 
2.  clovers  and  legumes;  3.  cole  crops  or  the  cabbage 
tribe ;  4.  roots  and  tubers. 

CEREALS  AND   GRASSES 

In  the  case  of  those  included  in  the  first  group,  the 
purpose  or  object  is  to  obtain  as  large  a  growth  of  leaf 
and  stem  as  possible.  Thus  the  character  of  the  fertili- 
zation may  differ  from  that  recommended  when  the  same 
crops  are  grown  for  the  primary  purpose  of  obtaining 
the  largest  yield  of  seed  or  grain.  These  crops,  too, 
may  in  all  cases  be  considered  as  only  well  adapted  for 
the  "  intensive "  system  of  practice  —  that  is,  when  the 
management  is  such  as  to  encourage  the  largest  yield 
possible  to  the  unit  of  area  under  the  existing  conditions 
of  climate  and  season.  The  natural  fertility  of  the  soil 
thus  becomes  a  less  important  factor;  indeed  it  cannot 

260 


Green  Forage  Crops  261 

be  relied  upon  altogether,  as  the  largest  yield  of  succulent 
food  is  dependent  upon  a  rapid  and  continuous  growth, 
and  hence  the  supply  of  plant-food  must  be  relatively 
much  greater  than  is  the  case  when  the  cereals  are  grown 
for  their  seed.  That  is,  forage  crops,  because  succulence 
is  a  factor  influencing  quality,  must,  as  a  rule,  be  grown 
quickly,  and  in  order  that  large  yields  may  be  obtained 
in  a  short  period  of  time  a  relatively  greater  abundance 
of  plant-food  must  be  at  their  disposal  than  when  the 
growth  is  distributed  through  a  longer  period.  Be- 
sides, larger  amounts  of  all  of  the  food  constituents 
are  required  for  the  production  of  the  same  amount  of 
dry  matter  to  the  acre  than  when  grown  for  the  mature 
crop,  because  the  dry  matter  of  the  mature  crop  is  richer 
in  the  constituents  derived  from  the  air  and  poorer  in 
those  derived  from  the  soil,  than  the  dry  matter  of  the 
immature  crop. 

Maize  (corn)  forage. 

A  valuable  forage  crop  of  the  first  group  is  maize 
(Indian  corn),  because  it  grows  quickly,  is  well  adapted 
to  a  wide  variety  of  soils  and  climates,  is  extremely  palat- 
able, and  is  capable  of  producing  large  yields.  The 
fertilization  which  has  been  recommended  for  the  field 
crop  is  less  desirable  than  one  which  furnishes  a  greater 
proportion  of  nitrogen,  because  of  the  greater  need  of 
this  element,  and  because  it  encourages  a  larger  leaf  and 
stalk  growth ;  and  the  greater  the  proportion  of  these  in 
a  corn  crop,  the  richer  will  be  the  dry  matter  in  the  im- 
portant compound  protein,  and  nitrogen  is  the  basic 
element  in  this  group  of  nutrients. 

When  the  crop  is  grown  on  good  land  on  clover  sod, 
which  has  been  liberally  manured,  the  fertilizers  applied 


262  Fertilizers 

should  be  particularly  rich  in  the  mineral  elements,  phos- 
phoric acid  and  potash.  An  application  of  500  pounds 
of  a  mixture  containing  — 

Nitrogen 2% 

Available  phosphoric  acid 6% 

Potash 8% 

would  provide  an  abundance  of  food,  even  should  un- 
favorable conditions  intervene,  but  when  grown  on  light, 
unmanured  soil  without  sod,  a  larger  amount  of  nitrogen 
should  be  used  in  connection  with  the  minerals.  An 
application  of  25  pounds  of  nitrogen,  35  of  phosphoric 
acid  and  50  of  potash  is  as  small  a  fertilization  as  should 
be  recommended  on  soils  of  this  character,  since  a  yield 
of  10  tons  to  the  acre,  containing  25  per  cent  of  dry  matter, 
—  which  is  only  a  fair  crop,  —  would  remove  60  pounds 
of  nitrogen,  25  of  phosphoric  acid  and  70  of  potash. 
Hence,  very  large  increases  in  yield  could  not  be  expected 
from  smaller  dressings,  unless  conditions  were  absolutely 
favorable  throughout  the  entire  period  of  growth.  The 
nitrogen,  as  in  the  case  of  field  corn,  may  be  derived  from 
organic  sources,  as  the  season  of  growth  is  the  same,  — 
the  summer,  —  which  is  the  most  favorable  for  encouraging 
a  rapid  change  of  the  organic  nitrogen  into  the  soluble 
nitrates.  The  phosphoric  acid  should  be  in  large  part 
derived  from  superphosphates,  though  since  the  season 
of  growth  and  the  character  of  the  crop  and  of  its  cultiva- 
tion are  conditions  all  of  which  favor  a  rapid  change  of 
insoluble  into  available  forms,  a  portion  may  be  sup- 
plied by  ground  bone  or  tankage.  The  potash  may  be 
kainit  or  muriate,  though  if  kainit  is  used,  it  should 
be  broadcasted  and  well  worked  into  the  soil  before 
planting. 


Green  Forage  Crops  263 

Silage  corn. 

Corn  grown  for  the  silo,  while  distinctly  a  forage  crop, 
is,  in  its  management,  very  similar  to  the  field  crop,  and 
is  not  planted  so  thickly  as  to  prevent  the  formation  of 
ears.  The  object  in  its  growth  is,  however,  to  obtain  a 
large  yield  of  dry  matter,  somewhat  richer  in  nitrogenous 
substance  and  poorer  in  starch  and  woody  fiber  than  field 
corn.  Hence  the  fertilizers  for  the  crop  on  medium  soils 
should  be  richer  in  nitrogen  than  for  the  field  corn,  where 
the  primary  object  is  the  grain,  and  where  heavy  fertiliza- 
tion with  nitrogen  would  encourage  a  disproportionate 
stalk  growth.  An  application  of  30  pounds  of  nitrogen 
(equivalent  to  250  pounds  of  dried  blood  or  450  of  cotton- 
seed meal),  40  of  phosphoric  acid  (equivalent  to  300 
pounds  of  acid  phosphate)  and  60  of  potash  (equivalent 
to  120  pounds  of  muriate  of  potash)  would  provide  for 
a  marked  increase  in  yield. 

Wheat  and  rye  forage. 

In  the  growth  of  cereal  grains,  the  object  is  to  secure 
as  large  a  yield  of  grain  as  is  possible  under  the  conditions 
of  climate  and  season,  and  only  such  development  of 
leaf  and  stem  as  will  contribute  to  a  maximum  yield  of 
grain.  Hence  a  too  liberal  nitrogenous  fertilization  which 
encourages  this  form  of  growth  may  result  in  too  great 
a  proportionate  yield  of  straw.  This  objection  becomes 
an  advantage  when  the  cereals  are  grown  for  forage. 

The  cereal  crops,  wheat  and  rye,  if  seeded  in  the  fall, 
should  therefore  receive  a  fertilizer  which  shall  especially 
promote  leaf  and  stem  growth;  and  to  accomplish  this 
purpose  in  the  best  manner,  a  rapid  early  fall  growth, 
and  a  consequent  deep  rooting  system,  as  well  as  an 


264  Fertilizers 

early  and  rapid  spring  growth,  should  be  encouraged. 
Fertilizers  most  suitable  are  rich  in  nitrogen  and  phos- 
phoric acid,  and  should  contain  potash  also,  if  the  land 
has  not  been  previously  well  supplied  with  this  element. 
The  larger  proportion  of  the  nitrogen,  however,  should 
be  applied  in  available  forms  as  a  top-dressing  in  the 
spring,  rather  than  at  time  of  seeding,  thus  reducing  the 
possible  loss  of  this  element  during  the  winter  and  early 
spring  through  leaching,  besides  providing  the  plant 
with  it  when  most  needed,  and  producing  a  crop  richer 
in  nitrogenous  substance. 

The  ranker  growth  and  somewhat  coarser  product 
resulting  from  this  method  of  fertilization,  while  not 
desirable  for  grain  crops,  is  not  a  detriment  when  the 
product  is  cut  in  its  green  stage  for  feeding,  and  the 
larger  growth  is  accompanied  by  greater  succulence. 

Where  these  cereal  grains  are  sown  mainly  as  catch 
crops  following  a  corn  crop  which  has  been  liberally  fer- 
tilized with  the  minerals  phosphoric  acid  and  potash, 
the  application  at  time  of  seeding  may  be  light,  and 
may  consist  only  of  nitrogen  and  phosphoric  acid,  — 
for  example,  from  200  to  400  pounds  to  the  acre  of  a  dis- 
solved bone;  and  the  top-dressing  in  the  spring  need 
not  exceed  100  pounds  of  nitrate  of  soda  to  the  acre  for 
the  wheat,  and  75  pounds  to  the  acre  for  the  rye.  For 
lighter  soils,  or  for  those  not  previously  well  fertilized, 
much  heavier  applications  not  only  are  required,  but  all  of 
the  constituents  should  be  included,  and  the  top-dressings 
should  be  made  in  the  spring,  as  already  pointed  out. 

Spring  rye. 

For  spring  rye,  an  application  of  a  fertilizer  furnishing 
10  pounds  of  nitrogen,  20  of  phosphoric  acid  and  10  of 


Green  Forage  Crops  265 

potash  to  the  acre  would  be  a  sufficiently  liberal  dressing 
for  the  crop  on  good  soils,  since  the  plant  possesses  good 
foraging  powers,  though  it  is  not  so  desirable  a  forage 
crop  for  northern  climates  as  the  winter  rye.  The  ni- 
trogen, in  any  case,  should  be  in  quickly  available  forms. 

Oats. 

Oats  and  millet  are  also  suitable  crops  for  forage  pur- 
poses, and  are  largely  grown;  the  first,  because  it  is 
adapted  for  cool,  moist  weather,  and  makes  a  rapid  early 
growth,  and  the  second,  because  adapted  for  late  spring 
seeding  and  for  summer  conditions. 

The  oat  crop  for  forage  purposes  is  even  more  generally 
benefited  by  manuring  than  when  grown  for  the  grain, 
and  the  constituents  particularly  useful  are  nitrogen  and 
phosphoric  acid,  though  on  sandy  soils,  and  on  those  of 
medium  fertility  and  not  previously  fertilized  with  potash, 
this  element  should  also  be  added. 

A  good  dressing,  keeping  in  mind  the  value  of  the 
possible  increased  yield,  may  consist  of  12  pounds  of 
nitrogen,  20  of  phosphoric  acid  and  10  of  potash,  —  the 
nitrogen  largely  in  the  form  of  a  nitrate  and  the  phos- 
phoric acid  in  soluble  and  available  forms. 

The  oat  crop  is  peculiar  in  that  shortly  after  the 
germination  of  the  seed  there  usually  occurs  a  period  of 
a  week  or  ten  days  during  which  the  growth  is  extremely 
slow,  which  experienced  farmers  call  the  "pouting" 
period.  While  the  exact  cause  of  this  well-known  habit 
is  not  understood,  it  is  believed  to  be  due  in  part  to  the 
absence  of  an  available  plant-food  of  the  right  sort  early 
in  the  season,  since  liberal  applications  of  nitrates  and 
superphosphates  seem  to  shorten  the  period  of  "pouting," 
if  not  altogether  preventing  its  occurrence.  Its  avoid- 


266  Fertilizers 

ance  for  grain  crops,  while  important,  is  not  so  impor- 
tant a  matter  as  in  the  case  of  forage  crops,  since  an  ex- 
tension of  the  period  of  growth  simply  delays  ripening, 
while  in  the  latter,  delays  not  only  prevent  maximum 
growth  within  a  certain  time,  but  seriously  interfere 
with  rotations. 

Winter  oats,  which  are  successfully  grown  in  the 
southern  sections  of  the  country,  should  be  fertilized 
at  time  of  seeding  practically  in  the  same  manner  as 
wheat;  that  is,  dressings  furnishing  small  amounts  of 
nitrogen  and  considerable  phosphoric  acid,  to  be  fol- 
lowed in  spring  with  a  top-dressing  of  nitrate  of  soda, 
not  to  exceed  100  pounds  to  the  acre. 

Oats  and  peas. 

Where  oats  are  grown  with  field  peas  for  the  purpose 
of  supporting  the  vines,  as  well  as  to  obtain  a  larger  yield 
than  from  either  alone,  the  fertilizer  should  also  contrib- 
ute toward  the  increase  in  the  pea  crop,  and  hence  a 
greater  abundance  of  the  minerals  should  be  applied, 
though  it  is  very  desirable  in  this  case,  too,  to  encourage 
the  rapid  growth  of  the  oats  by  reasonably  liberal  supplies 
of  available  nitrogen.  (See  Fig.  23,  Plate  XII.) 

Barley  and  peas. 

The  growth  of  this  combination  of  plants  is  a  desirable 
one  when  late  fall  forage  is  needed,  and  as  a  crop,  is  well 
adapted  for  fall  conditions.  The  fertilization  should 
be  liberal,  in  order  to  encourage  a  rapid  and  large  appro- 
priation of  food,  which  may  be  elaborated  after  light 
frosts  occur.  An  application  of  200  pounds  to  the  acre 
of  a  mixture  of  100  pounds  of  nitrate  of  soda,  175  of  acid 
phosphate  and  25  of  muriate  of  potash  will  furnish  suffi- 
cient and  good  proportions  of  the  plant-food  constituents. 


Green  Forage  Crops  267 

Millet 

The  various  kinds  of  millet  are  eminently  surface 
feeders,  and  are  particularly  benefited  by  liberal  ap- 
plications of  all  the  fertility  elements.  In  fact,  maximum 
forage  crops  of  this  plant  cannot  be  obtained  except  when 
there  is  present  in  the  soil  such  an  abundance  of  all  of  the 
fertility  elements  as  to  enable  a  continuous  and  rapid 
growth.  Both  the  nitrogen  and  phosphoric  acid  should 
be  largely  in  immediately  available  forms ;  hence  nitrates 
and  superphosphates  are  recommended.  The  potash  may 
be  in  the  form  of  muriate.  A  crop  of  ten  tons  to  the 
acre  of  millet  forage,  of  any  of  the  Japanese  varieties, 
which  are  very  suitable  for  this  purpose,  will  remove  50 
pounds  of  nitrogen,  25  of  phosphoric  acid  and  110  of 
potash,  practically  all  of  which  food  is  absorbed  from  the 
immediate  surface  soil.  Good  crops  frequently  reach  this 
assumed  yield ;  hence,  unless  the  land  is  in  a  high  state 
of  fertility,  or  has  been  previously  fertilized,  it  is  neces- 
sary, in  order  to  obtain  a  fair  crop,  to  furnish  by  direct 
application  at  least  one-half  of  the  nitrogen  and  potash, 
and  as  much  phosphoric  acid,  as  are  contained  in  the  crop. 
These  amounts  and  kinds  of  plant-food  could  be  practically 
supplied  by  a  dressing  of  450  pounds  of  a  mixture  made 
up  of  150  pounds  of  nitrate  of  soda,  200  of  acid  phos- 
phate and  100  of  muriate  of  potash,  and  such  dressings 
have  given  excellent  satisfaction  in  the  New  Jersey  experi- 
ments with  forage  crops. 

Orchard-grass. 

Orchard-grass  is  among  the  earliest  grasses  that  are 
useful  for  soiling  or  for  pasture.  It  possesses  many 
valuable  characteristics,  and  is  worthy  of  more  careful 


268  Fertilizers 

attention  than  is  usually  accorded  it.  Its  chief  advan- 
tage lies  in  the  fact  that  it  is  ready  for  use  two  or  three 
weeks  earlier  than  the  grasses  ordinarily  grown;  it  is 
a  plant,  also,  that  makes  a  very  heavy  growth  under  good 
conditions  of  soil  and  season. 

Like  other  grasses,  orchard-grass  requires  an  abun- 
dance of  available  nitrogenous  food,  and  therefore  the 
promise  of  a  crop  is  very  much  increased  by  the  applica- 
tion of  manures  or  fertilizers  containing  nitrogen  at  the 
time  of  seeding,  and  by  top-dressing  with  nitrate  of  soda 
in  early  spring.  A  good  formula  or  mixture  for  time  of 
seeding  is  the  following : 

Nitrate  of  soda 100  Ibs. 

Tankage 200  Ibs. 

Acid  phosphate 600  Ibs. 

Muriate  of  potash 100  Ibs. 

An  application  of  400  to  600  pounds  of  such  a  mixture 
well  harrowed  into  the  soil  with  a  spring  top-dressing  of 
100  to  150  pounds  of  nitrate  of  soda  should  amply  supply 
the  requirements  of  an  abundant  crop. 

Italian  rye-grass. 

Another  grass  that  has  received  some  attention  as  a 
forage  crop,  particularly  for  summer  pasture  and  soiling, 
is  Italian  rye-grass.  It  is  especially  suitable  for  moist 
soils,  or  for  soils  that  can  be  irrigated,  and  responds 
very  profitably  to  the  application  of  water  or  heavy 
fertilization.  The  fertilization  of  this  crop  may  be  the 
same  as  that  recommended  for  orchard-grass,  except 
where  irrigation  is  practiced,  in  which  case  less  available 
nitrogen  should  be  used  because  it  is  likely  to  be  lost  by 
leaching. 


Green  Forage  Crops  269 

Bermuda-grass. 

In  the  southern  states,  Bermuda-grass  is  considered  one 
of  the  most  valuable  grasses  for  pasture.  It  is  dis- 
tinctly a  hot  weather  plant,  and  thrives  only  in  those 
regions  which  have  short,  mild  winters.  Fortunately,  it 
is  well  adapted  for  pasture  on  poor  lands,  and  its  power  of 
withstanding  a  drought  is  one  of  its  valuable  characteris- 
tics. Because  it  is  capable  of  producing  a  new  plant  at 
each  joint,  it  spreads  rapidly,  and  it  is  this  quality  which 
makes  it  a  valuable  pasture  grass  as  well  as  an  aggressive 
and  pestiferous  weed.  However,  it  can  be  eradicated 
from  a  field  where  it  is  not  wanted  with  comparative  ease 
by  proper  cultivation.  At  the  time  of  seeding,  the  soil 
should  be  well  supplied  with  minerals,  and  top-dressings 
of  nitrate  of  soda  should  be  made  in  spring. 

CLOVERS  AND  OTHER  LEGUMES 

There  are  four  types  of  true  clover  —  red  clover  and 
mammoth  red  clover,  a  variety  of  the  former,  alsike  clover, 
crimson  clover,  white  clover  —  which  are  among  the  most 
valuable  of  our  summer  forage  crops:  first,  because  of 
the  time  of  their  growth,  they  furnish  food  before  spring- 
sown  crops  are  ready ;  second,  because  of  their  power  of 
acquiring  food  from  sources  inaccessible  to  the  cereals,  they 
are  less  exhaustive ;  and  third,  they  are  especially  rich  in 
the  compound  protein,  the  most  useful  substance  con- 
tained in  feeds.  Since  these  crops  generally  grow  well 
on  soils  of  medium  fertility,  many  are  inclined  to  regard 
them  as  able  to  subsist  and  make  a  good  crop  without 
liberal  fertilization.  It  should  be  remembered,  however, 
that  the  power  which  these  plants  possess  of  acquiring 


270  Fertilizers 

nitrogen  from  the  air  depends  largely  upon  the  supply 
at  their  command  of  the  mineral  elements,  phosphoric  acid, 
potash  and  lime ;  the  presence  of  these  is  of  primary  im- 
portance, and  good  crops  cannot  be  grown  on  land  deficient 
in  these  elements.  In  any  event,  therefore,  liberal  supplies 
of  the  minerals  should  be  provided,  in  order  that  maximum 
yields  may  be  obtained.  (See  Fig.  24,  Plate  XI.)  On  soils 
of  medium  fertility  which  are  fairly  well  supplied  with 
vegetable  matter,  the  need  for  nitrogen  is  not  marked, 
even  in  the  early  growth  of  the  plant.  On  lighter  soils, 
however,  a  nitrogenous  fertilization  is  often  serviceable, 
because  supplying  nitrogen  before  the  plant  has  acquired 
the  power  of  obtaining  it  from  the  air.  This  practice 
enables  the  plant  to  make  an  early  start,  and  prevents 
the  delay  in  growth  which  sometimes  occurs,  particularly 
on  light  soils,  during  the  period  immediately  after  germina- 
tion, when  the  plant  is  unable  to  obtain  its  nitrogen  from 
sources  other  than  the  soil.  A  green  forage  crop  averaging 
10  tons  to  the  acre  requires,  on  the  average,  about  30 
pounds  of  phosphoric  acid  and  100  of  potash,  and  the 
nitrogen  which  necessarily  accompanies  these  amounts 
of  minerals  will  reach,  on  the  average,  100  pounds.  If 
this  element  is  drawn  from  the  air,  because  provided  with 
an  abundance  of  minerals,  it  is  manifestly  economy  to 
supply  the  full  amount  of  these  required,  rather  than 
omit  them,  and  thus  to  limit  the  plant's  power  of  acquiring 
this  expensive  element,  since  the  value  of  the  100  pounds 
of  nitrogen  gained  is  greater  than  the  cost  of  both  the 
phosphoric  acid  and  potash  required.  The  fertilization 
of  these  various  clovers  may  be  much  the  same;  in 
general  an  application  of  200  pounds  of  acid  phosphate 
and  100  of  muriate  of  potash  should  be  sufficient,  espe- 
cially if  they  follow  a  well-fertilized  crop,  such  as  potatoes. 


Green  Forage  Crops  271 

Japan  clover. 

Japan  clover,  though  not  a  true  clover,  is  valuable 
as  a  pasture  crop  because  it  is  well  adapted  to  poor  and 
light  lands  and  withstands  drought  well,  growing  and 
spreading  when  other  plants  die  for  lack  of  moisture.  It 
thrives  from  Virginia  southward  and  as  far  west  as  Kansas. 
It  is  seldom  fertilized,  even  though  it  is  much  like  other 
clovers  and  responds  to  liberal  applications  of  the  minerals. 

Cowpea  and  soybean. 

The  clovers,  which  range  in  their  length  of  life  from 
annuals  to  perennials,  are,  too,  able  to  obtain  their  neces- 
sary supplies  of  minerals  more  readily  from  soil  sources 
than  the  distinctly  summer  crops,  as  the  cowpea  and  soy- 
bean, because  of  the  longer  period  of  preparatory  growth 
in  the  case  of  the  former.  That  is,  clover  or  vetch,  while 
it  does  make  a  very  rapid  growth  through  a  short  period, 
does  not  obtain  all  of  its  food  during  that  period.  In  its 
preparatory  stage  of  growth  —  fall  and  early  spring  —  a 
very  considerable  amount  of  food,  the  larger  proportion, 
in  many  instances,  is  obtained,  which  in  its  later  stages 
of  growth  is  simply  distributed  throughout  the  entire 
plant ;  while  the  cowpea  and  soybean,  on  the  other  hand, 
must  obtain  the  entire  amount  of  food  needed  for  their 
growth  and  development  during  a  short  period,  and  these 
crops  reach  their  best  stage  of  development  for  forage 
in  two  and  one-half  to  three  months  from  time  of  planting. 
Hence,  these  crops,  which  possess  apparently  greater 
foraging  powers,  and  make  their  development  during 
the  season  when  conditions  are  most  favorable  for  rapid 
change  of  insoluble  to  soluble  food  in  the  soil,  require, 
when  the  conditions  of  the  land  are  the  same  in  each  case, 


272  Fertilizers 

a  relatively  greater  abundance  of  the  mineral  elements 
than  do  the  clovers,  which  can  acquire  food  through  a 
longer  period. 

An  application  of  300  pounds  to  the  acre  of  a  mixture 
of  200  pounds  of  acid  phosphate  and  100  of  muriate  of 
potash,  which  supplies  25  pounds  of  phosphoric  acid  and 
50  of  potash,  would,  on  medium  soils,  be  regarded  as  a 
sufficient  annual  dressing  for  clover  crops;  whereas,  in 
the  case  of  the  purely  summer  crops,  the  application 
could  be  increased  one-half  with  profit.  In  the  case  of 
the  summer  crop,  the  phosphoric  acid  should  be  in  a 
soluble  form,  because  it  is  not  economy  to  depend  upon 
the  conditions  of  climate,  soil  and  season  to  change  in- 
soluble forms  rapidly  enough  to  provide  for  the  con- 
tinous  feeding  of  the  plant,  while  for  the  clovers,  less 
available  forms  may  be  used  with  advantage. 

Spring  vetch. 

Spring  vetch  may  be  substituted  for  Canada  field  peas 
in  a  mixture  with  oats ;  and  in  the  northern  states,  where 
the  pea-louse  has  been  very  destructive,  it  serves  an 
excellent  purpose.  It  is  sown  in  spring  or  early  summer, 
and  does  not  survive  the  winter.  The  preparation  of 
soil  and  fertilization  should  be  practically  the  same  as 
recommended  for  oats  and  peas. 

Hairy  or  winter  vetch. 

Hairy  vetch  is  used  extensively  as  a  cover-crop  or  green- 
manure,  and  its  use  in  combination  with  wheat  or  rye  as  a 
forage  crop  is  increasing  rapidly.  The  chief  advantage  of 
the  use  of  hairy  vetch  with  wheat  or  rye  lies  in  the  fact 
that  a  larger  crop  of  forage  may  be  secured  than  when  the 
cereal  is  grown  alone.  The  fertilization  should  be  the 


Green  Forage  Crops  273 

same  as  recommended  for  the  cereal  with  which  it  is  grown, 
except  that  the  amount  of  nitrogen  may  be  slightly  re- 
duced. A  liberal  supply  of  minerals  should  be  applied. 

Alfalfa,  or  lucerne. 

This  valuable  crop,  which  was  not  formerly  regarded 
as  well  adapted  for  the  eastern  states,  can  be  success- 
fully and  profitably  grown  ft  the  soil  is  sufficiently  deep 
and  open  and  naturally  well  drained,  and  provided  it  is 
supplied  with  an  abundance  of  mineral  food,  consisting 
of  phosphoric  acid,  potash  and  lime.  Its  habits  of  growth 
are  such  as  to  enable  the  harvesting  of  three  or  four  green 
forage  crops,  and  at  least  two  hay  crops  annually.  In 
order  to  meet  the  large  plant-food  demands  thus  made, 
the  fertilization  previous  to  seeding  must  be  not  only 
liberal,  but  frequent  top-dressings  should  be  made.  The 
phosphoric  acid  for  these  dressings  should  preferably  be 
drawn  from  superphosphates,  in  order  that  ready  dis- 
tribution may  be  accomplished,  while  a  large  portion  of 
that  contained  in  the  preparatory  dressing  may  consist 
of  the  less  soluble  forms,  as  ground  bone,  natural  phos- 
phatic  guanos,  and  fine  ground  rock  phosphates. 

Twenty  tons  of  alfalfa  green  forage,  which  may  be 
regarded  as  a  good  annual  yield  for  this  plant  from  the 
two  to  four  cuttings  that  may  be  made,  will  contain 
250  pounds  of  nitrogen,  50  of  phosphoric  acid  and  275 
of  potash.  Assuming  that  the  demands  for  soil  nitrogen 
are  confined  to  a  short  period  immediately  subsequent 
to  the  germination  of  the  seed,  the  total  required  plant- 
food  is  still  considerable,  and  is  especially  severe  upon 
the  potash  compounds  of  the  soil.  Hence,  the  fertilizers 
supplied  should  be  particularly  rich  in  this  element.  For 
eastern  conditions,  where  soils  possess  a  medium  rather  than 


274  Fertilizers 

a  high  potential  fertility,  heavy  dressings  of  the  minerals 
should  always  be  made.  A  good  preparatory  fertilizer  may 
consist  of  20  pounds  of  nitrogen,  equivalent  to  125  pounds 
of  nitrate  of  soda ;  75  of  phosphoric  acid,  equivalent  to 
600  of  acid  phosphate ;  and  200  of  actual  potash,  equivalent 
to  400  pounds  of  muriate  of  potash  to  the  acre ;  and  an- 
nual top-dressings  should  provide  at  least  30  pounds  of 
phosphoric  acid  and  100  of  actual  potash  for  the  same  area. 
Inasmuch  as  careful  preparation  of  soil  is  necessary 
previous  to  seeding,  and  since  this  can  preferably  be 
accomplished  by  the  growth  of  cultivable  crops,  the 
fertilizers  may  be  also  partly  applied  to  these  rather 
than  all  at  once  immediately  preceding  the  seeding, 
thus  limiting  danger  of  injury  to  germination  by  an 
application  of  so  large  a  proportion  of  salts. 

Sweet  clover. 

The  use  of  sweet  clover  is  spreading  very  rapidly  in 
the  United  States.  While  its  growth  and  purpose  of 
growth  are  very  much  the  same  as  alfalfa,  it  does  not 
seem  to  require  nearly  as  much  fertilization,  and  it  is  not 
uncommon  to  produce  enormous  yields  of  forage  or  hay 
upon  good  soils  without  any  fertilization.  Its  culture 
may  be  the  same  as  alfalfa,  but  it  has  been  found  more 
profitable  in  most  localities  to  sow  it  in  grain  in  spring 
when  the  ground  is  honeycombed.  In  this  case  no  fer- 
tilization is  needed.  If  sown  alone,  moderate  quantities 
of  the  minerals  should  be  supplied.  It  thrives  especially 
well  in  hard,  compact  soils,  rich  in  lime. 

Need  of  lime  for  legumes. 

Another  point  that  should  be  remembered  in  the 
fertilization  of  the  leguminous  plants  is  their  need  for 


Green  Forage  Crops  275 

lime.  This  is  true  of  the  clovers  particularly,  not  only 
for  the  purpose  of  providing  the  plants  with  a  sufficient 
amount  of  this  element,  but  in  order  that  any  possible 
acidity  of  soil  may  be  corrected,  since  the  bacterial  life 
in  the  soil,  which  is  essential  in  order  that  the  plant  may 
acquire  its  nitrogen  from  the  air,  is  discouraged  rather 
than  encouraged  by  the  presence  of  acid.  Hence,  all 
soils  that  are  used  for  the  frequent  growth  of  leguminous 
crops  should  receive  a  dressing  of  lime,  preferably  in  the 
fall  ;  25  bushels  of  stone  lime  to  the  acre,  or  its  equivalent 
of  ground  limestone.  Once  in  four  or  five  years  is  a 
sufficient  amount  for  medium  soils. 

Fertilization  of  soiling  crops. 

The'  necessity  for  fertilization,  and  the  method  em- 
ployed in  "intensive"  practice,  are  illustrated  by  the 
following  scheme  of  growing  soiling  crops,  now  practiced 
at  the  Experiment  Farm  in  New  Jersey.  If  an  abundance 
of  food  is  not  supplied,  the  continuous  feeding  and  con- 
sequent constant  and  rapid  growth  of  the  plants,  which 
are  primary  necessities  of  the  system  in  order  to  maintain 
the  rotation  and  to  obtain  maximum  yields,  are  prevented. 
With  proper  management  in  other  respects,  the  scheme 
of  rotation  and  fertilization  will  result  in  a  gradual  in- 
crease in  the  fertility  of  the  soil. 

SCHEME  OF  SOILING  CROPS 

No.  OF    CROP  Ro-  TIME  OF  AMOUNT  OF  TIME  OF 

ACRE       TATION  SEEDING  FERTILIZER  APPLIED        HARVESTING 


Crim.cn  c,over 


Au*.  11,  -97  {  '«  lb.  Ajjd  phospha^  j  M&y  ^ 


f  100  Ib.  Acid  phosphate       ] 

Corn       .....     June  20,  '98  j     50  Ib.  Ground  bone  [  Aug.  20,  '98 

I    50  Ib.  Muriate  of  potash  J 

„  f    25  Ib.  Nitrate  of  soda       } 

Barley  and  Peas       .     Aug.  25,  '98     100  lb.  Acid  phosphate          Oct.  25,  '98 

I    50  lb.  Muriate  of  potash  J 


276 


Fertilizers 


No.  OP    CROP  Ro- 

TIME  op 

AMOUNT  op 

TIME  OP 

ACRE          TATION 

SEEDING 

FERTILIZER  APPLIED 

HARVESTING 

Crimson  clover    . 

.     Aug.  24,  '97  „ 

100  Ib.  Acid  phosphate       ] 
50  Ib.  Muriate  of  potash 

May  10,  '98 

June  10,  '98  . 

100  Ib.  Acid  phosphate 

Aug.  10,  '98 

2 

50  Ib.  Muriate  of  potash 

25  Ib.  Nitrate  of  soda 

Barley  and  Peas 

100  Ib.  Acid  phosphate 

>  Oct.  25,  '98 

50  Ib.  Muriate  of  potash 

50  Ib.  Nitrate  of  soda 

.     May  20,  '98  - 

100  Ib.  Acid  phosphate 
50  Ib.  Ground  bone 

July  20,  '98 

3 

50  Ib.  Muriate  of  potash 

- 

75  Ib.  Nitrate  of  soda 

Millet         .    .    . 

Aug    1,  '98 

150  Ib.  Acid  phosphate 

Oct.    1,    '98 

75  Ib.  Muriate  of  potash 

50  Ib.  Nitrate  of  soda 

.     May  10,  '98 

100  Ib.  Acid  phosphate 
50  Ib.  Ground  bone 

July  10,  '98 

4 

50  Ib.  Muriate  of  potash 

25  Ib.  Nitrate  of  soda 

Barley  and  Peas  . 

.    Aug.  10,  '98  • 

100  Ib.  Acid  phosphate 

•  Oct.  10,  '98 

50  Ib.  Muriate  of  potash 

'      ' 

150  Ib.  Acid  phosphate 

Wheat    .... 

Sept.  28,  '97 

50  Ib.  Ground  bone 

June  5,   '98 

25  Ib.  Muriate  of  potash  , 

25  Ib.  Nitrate  of  soda       ] 

5 

Oats  and  Peas      . 

.     April  20,  '98 

100  Ib.  Acid  phosphate       1  _        2n  ,QR 
25  Ib.  Ground  bone              June  20'   9! 

50  Ib.  Muriate  of  potash  J 

Soybeans    .     .     . 

.     Aug.   1,  '98  < 

f  200  Ib.  Acid  phosphate       \  n  f     *     ,qfi 
I  100  Ib.  Muriate  of  potash  / 

150  Ib.  Acid  phosphate 

Rye        .... 

50  Ib.  Ground  bone 

May  1,   '98 

25  Ib.  Muriate  of  potash  J 

75  Ib.  Nitrate  of  soda 

6 

Millet     .... 

May  1,   '98  - 

150  Ib.  Acid  phosphate 

July   1,   '98 

.    75  Ib.  Muriate  of  potash 

Cowpeas     .    .    . 

.     July  20,  '98  < 

200  Ib.  Acid  phosphate 
100  Ib.  Muriate  of  potash 

•  Sept.  20,  '98 

25  Ib.  Nitrate  of  soda 

Oats  and  Peas     . 

.     April  10,  '98 

100  Ib.  Acid  phosphate 
25  Ib.  Ground  bone 

June  10,  '98 

50  Ib.  Muriate  of  potash 

7 

Soybeans    .     .     . 

.     July   1,    '98 

f  200  Ib.  Acid  phosphate 
1  100  Ib.  Muriate  of  potash 

|  Sept.  1,  '98 

f    25  Ib.  Nitrate  of  soda       } 

Barley  and  Peas 

.     Sept.  1,  '98 

100  Ib.  Acid  phosphate 

Nov.  1,  '98 

>    50  Ib.  Muriate  of  potash  J 

Green  Forage  Crops 


277 


No.  OF    CROP  Ro- 

ACRB          TATION 


Oats  and  Peas     , 
Cowpeas     .    . 
Barley  and  Peas 

Rye  and  Vetch 
Corn 


Barley  and  Peas 


TIME  OP 
SEEDING 


April  1,  '98 


June  15,  '98 


AMOUNT  OP 
FERTILIZER  APPLIED 

25  Ib.  Nitrate  of  soda 
100  Ib.  Acid  phosphate 
25  Ib.  Ground  bone 
50  Ib.  Muriate  of  potash 

200  Ib.  Acid  phosphate 


TIME  OP 
HARVESTING 


100  Ib.  Muriate  of  potash  / 


June  1, 


Aug.  15,  '98 


125  Ib.  Nitrate  of  soda 
100  Ib.  Acid  phosphate       \  Oct.  20,  '98 
50  Ib.  Muriate  of  potash 

125  Ib.  Nitrate  of  soda       ] 
150  Ib.  Acid  phosphate       [  May  5,  '98 
75  Ib.  Muriate  of  potash  J 

{  100  Ib.  Acid  phosphate       } 

June  1,  '98  j     50  Ib.  Ground  bone  [  Aug.   1,  '98 

I    50  Ib.  Muriate  of  potash  j 

125  Ib.  Nitrate  of  soda       } 
100  Ib.  Acid  phosphate       |  Oct.  15,  '98 
50  Ib.  Muriate  of  potash  J 


This  scheme,  which  provides  for  two  or  three  crops 
each  season,  has  proved  entirely  practicable  and  success- 
ful when  liberal  fertilization  is  practiced,  as  here  indicated. 


THE  CABBAGE  TRIBE 

Several  members  of  the  mustard  family  of  the  cabbage 
kind  are  useful  forage  crops,  and  their  cultivation  is  rapidly 
increasing.  In  general  feeding  practice,  they  may  be 
compared  with  root  crops.  In  fact,  kohlrabi  is  often 
classed  with  root  crops,  and  well  it  may  be,  since  it  is 
very  closely  allied  to  the  turnips  and  rutabagas,  differing 
chiefly  in  having  the  thickened  part  above  the  ground  rather 
than  below  ground.  The  leading  cabbage-like  forage  plants 
are  rape,  cabbage  and  kohlrabi.  The  kales  are  not  much 
grown  for  forage  in  North  America.  Their  culture  does 
not  differ  greatly  from  that  of  rape.  Thousand-headed 
kale  is  the  kind  mostly  recommended,  but  it  does  not  ap- 
pear to  have  any  advantage  over  rape  for  forage. 


278  Fertilizers 

Rape.     (See  Fig.  25,  Plate  XIII.) 

Although  rape  does  well  in  soils  of  medium  fertility, 
the  best  results  are  secured  when  they  are  naturally 
rich,  or  have  been  well  fertilized.  When  grown  for 
forage,  an  application  of  barnyard  manure  at  the  rate  of 
8  tons  to  the  acre,  well  worked  into  the  surface  soil,  is 
desirable,  because  the  plant  is  a  voracious  feeder.  For 
its  best  growth  it  must  have  abundance  of  available 
nitrogen.  Hence,  if  manures  are  not  readily  obtainable, 
an  application  of  fertilizers  rich  in  nitrogen  should  be 
applied.  Experience  has  shown  that  a  fertilizer  con- 
taining 

Nitrogen      . 5% 

Phosphoric  acid  (available) 8% 

Potash 9% 

applied  at  the  rate  of  600  pounds  to  the  acre,  will  supply 
the  food  in  good  proportions.  Should  the  season  be 
unfavorable  for  rapid  growth,  an  additional  application 
of  100  pounds  to  the  acre  of  nitrate  of  soda  when  plants 
have  well  started  will  stimulate  growth  and  help  to  insure 
a  large  crop.  This  top-dressing  of  nitrate  of  soda  should 
be  made  when  the  plants  are  dry.1 

Cabbage. 

Among  those  forage  crops  grown  for  late  use,  there  is 
none  capable  of  producing  the  large  tonnage  which  may 
be  secured  from  cabbage  when  it  is  efficiently  attended. 
It  has  not  been  grown  to  any  extent  in  this  country  for 
feeding  live-stock,  but  a  knowledge  of  its  value  for  this 
purpose  is  undoubtedly  extending.  It  is  a  voracious 

1  Voorhees,  "Forage  Crops.'! 


Green  Forage  Crops  279 

feeder,  and  if  it  is  to  be  grown  successfully  for  forage  it 
should  be  liberally  fertilized.  Twenty  to  25  tons  of 
manure  should  be  applied  before  plowing,  1500  pounds 
of  lime  after  plowing,  and  just  previous  to  seeding  100 
pounds  of  nitrate  of  soda,  700  of  acid  phosphate  and  200 
of  muriate  of  potash  to  the  acre.  It  is  important  that 
these  applications  be  uniformly  made,  and  that  the  lime 
should  not  be  omitted,  because  it  is  a  safeguard  against 
a  disease  known  as  club-root  or  finger-and-toe. 

Kohlrabi. 

Kohlrabi  attains  its  best  development  when  grown  upon 
rich  soils,  and  proves  a  valuable  forage  crop,  especially 
because  it  may  be  fed  at  any  period  of  growth  without 
risk.  It  may  be  grown  upon  any  soils  suitable  to  ruta- 
bagas, and  its  culture  and  fertilization  may  be  the  same. 

ROOT  CROPS 

These  crops  are,  as  a  class,  exhaustive  of  plant-food 
elements,  much  more  so,  in  proportion  to  the  dry  matter 
contained  in  them,  than  the  cereals  or  legumes.  It 
will  require,  for  example,  20  tons  of  topped  fodder-beets 
or  turnips  to  furnish  as  much  total  food  as  is  contained 
in  10  tons  of  corn  forage  or  silage,  as  the  former  seldom 
contain  more  than  10  per  cent  of  dry  matter,  whereas  the 
latter  frequently  contain  more  than  20  per  cent;  yet  on 
the  average,  20  tons  of  roots  will  contain  60  pounds  of 
nitrogen,  equivalent  to  400  pounds  nitrate  of  soda,  35 
of  phosphoric  acid,  equivalent  to  300  pounds  of  acid 
phosphate,  and  150  of  potash,  equivalent  to  300  of  muriate 
of  potash,  which  amounts  are  far  in  excess  of  those  con- 
tained in  a  corn  crop,  particularly  of  the  minerals,  phos- 


280  Fertilizers 

phone  acid  and  potash.  The  nitrogen  demands  for  the 
two  crops  are  practically  identical.  In  the  case  of  both 
kinds  of  crops,  these  fertility  constituents  are  obtained 
entirely  through  the  roots  from  soil  sources. 

In  respect  to  fertilization,  however,  the  root  crops 
may  be  divided  into  two  groups,  very  similar  in  their 
demands  for  plant-food,  the  first  to  include  mangel- 
wurzels,  fodder-beets,  sugar-beets  and  carrots,  and  the 
second  turnips,  swedes  (rutabagas)  and  rape. 

Fertilizers  for  fodder-beets,  sugar-beets  and  carrots. 

The  first  group  requires  that  the  fertilization  with 
nitrogen  and  phosphoric  acid  shall  be  liberal,  and  that 
these  constituents  shall  be  applied  in  readily  soluble 
forms,  in  order  to  meet  the  large  and  early  demands  of 
the  plant  for  them.  Potash  is  also  a  very  essential 
constituent,  particularly  upon  soils  of  a  light,  sandy 
character;  upon  clay  loams  the  plant  is  better  able  to 
obtain  this  element. 

In  order  to  obtain  a  large  amount  of  actual  food  by 
the  growth  of  these  crops,  a  large  tonnage  must  be  secured, 
and  a  large  yield  cannot  be  obtained  unless  provision  is 
made  for  a  continuous  and  rapid  growth,  and  this  again 
cannot  be  accomplished  without  an  abundant  supply  of 
nitrogen  and  phosphoric  acid,  which,  as  already  stated, 
are  the  elements  which,  more  than  any  others,  seem  to 
rule  the  crop. 

In  the  case  of  sugar-beets,  the  suggestion  for  fertiliza- 
tion when  grown  for  sugar  (Chapter  XVII)  may  be  fol- 
lowed in  large  part.  That  is,  particular  attention  should 
be  given  to  the  supply  of  nitrogen  and  phosphoric  acid, 
though  when  grown  for  forage  it  is  important  not  only  to 
secure  sugar,  which  constitutes  a  large  proportion  of  the 


Green  Forage  Crops  281 

dry  matter,  but  that  the  gross  yield  shall  be  much  greater 
than  in  the  former  case.  Hence,  a  liberal  use  of  yard 
manure  need  not  be  avoided,  and  heavier  dressings  of 
nitrogen,  which  stimulates  early  leaf  growth,  may  be 
made. 

For  both  fodder-beets  and  sugar-beets,  an  application 
to  the  acre  of  40  pounds  of  nitrogen,  50  of  phosphoric 
acid  and  100  of  potash,  or  1000  pounds  of  a  fertilizer, 
containing  — 

Nitrogen 4% 

Available  phosphoric  acid 5% 

Potash 10% 

should  insure  a  very  considerable  increase  in  yield  on 
soils  of  medium  fertility,  provided  the  elements  are  drawn 
from  the  best  materials.  On  light  soil  the  fertilization 
should  be  still  heavier,  and  the  proportion  of  nitrogen 
increased.  In  fact,  on  soils  poor  in  fertility  and  possessing 
good  physical  qualities,  the  contributions  of  plant-food 
by  them  may  be  largely  ignored,  and  the  dressings  made 
large  enough  to  supply  the  entire  amount  of  food  required 
by  the  crop.  On  such  soils  the  nitrogen  should  prefer- 
ably be  applied  in  fractional  dressings  and  in  quickly 
available  forms,  because  it  is  essential  that  this  element 
should  be  quickly  absorbed  by  the  growing  plant.  The 
minerals  may  be  all  applied  in  one  dressing,  though 
preferably  in  two,  in  order  that  the  constituents  may  be 
well  distributed  throughout  the  surface  soil.  To  better 
accomplish  this,  cultivation  should  follow  each  application. 

Turnips  and  swedes. 

In  the  case  of  the  second  class  of  crops,  it  has  been 
shown  that  they  are  able  to  extract  their  phosphoric  acid 


282  Fertilizers 

from  combinations  not  readily  accessible  to  other  plants. 
In  fact,  they  respond  so  promptly  to  applications  of  this 
element  that  frequently  too  little  attention  is  given  to 
the  supplies  of  the  other  elements ;  yet  in  order  to  obtain 
satisfactory  yields,  these  must  also  be  added.  An  anal- 
ysis of  the  turnip,  for  example,  shows  it  to  be  rich  in 
potash;  hence  it  must  naturally  be  a  voracious  feeder 
upon  compounds  containing  this  element,  and  while  it 
seems  to  obtain  it  more  readily  from  soil  sources  than 
many  other  plants,  these  supplies  should  not  be  depended 
upon,  even  on  good  soils,  to  meet  its  entire  needs  in  this 
respect.  A  liberal  supply  of  nitrogen  is  also  demanded, 
particularly  during  the  early  growth.  An  application  of  a 
fertilizer  containing  20  pounds  of  nitrogen,  derived  in  part 
from  nitrate,  40  of  phosphoric  acid,  derived  in  large  part 
from  phosphates,  and  40  of  potash,  derived  from  muriates, 
would  be  a  fair  dressing  on  soils  of  good  character.  On 
the  poorer  soils,  the  application  of  the  constituents  of  the 
same  kind  and  forms  should  be  very  largely  increased. 

In  these  crops,  as  in  those  already  mentioned,  it  is  es- 
sential —  and  success  depends  upon  this  as  much  as  upon 
any  other  factor  —  that  the  growth  should  be  continuous ; 
and  in  order  that  there  shall  be  no  delay  in  this  respect, 
there  must  be  an  abundance  of  available  food  always  at 
their  command. 

TUBER  CROPS 

In  many  sections  the  potato  and  sweet  potato  are 
grown  for  roughage.  For  these  crops  no  different  fer- 
tilization is  recommended  than  that  already  outlined 
(Chapter  XIII)  for  the  crops  when  grown  for  market, 
though  in  the  case  of  sweet  potatoes,  soils  not  adapted 
for  the  growth  of  marketable  tubers  may  be  used. 


CHAPTER  XV 
MARKET-GARDEN  CROPS 

A  KNOWLEDGE  of  the  principles  of  plant  nutrition  is 
perhaps  more  serviceable  in  market-gardening  than  in 
any  other  line  of  farming.  This  branch  of  farming  cannot 
be  profitably  conducted  either  without  suitable  soils  or 
without  an  abundant  supply  of  plant-food.  Both  of 
these  conditions  are  essential  for  the  growth  of  high-class 
products. 

THE  YIELD  AND  QUALITY  DEPENDENT  UPON   CONTINUOUS, 
AND  RAPID  GROWTH 

In  these  days,  it  is  not  only  the  yield  of  a  definite  area 
that  must  be  considered,  but  the  edible  quality  of  the 
products  that  are  put  upon  the  market.  Quality  depends 
upon,  or  is  measured  by,  both  appearance  and  palata- 
bility;  and  palatability  is  determined  by  the  succulence 
and  sweetness  of  the  vegetable,  or  its  freedom  from  bitter- 
ness, stringiness,  and  other  undesirable  characteristics 
which  frequently  exist,  and  which  can  be  largely  eliminated 
provided  the  grower  is  thoroughly  familiar  with  his  busi- 
ness, assuming,  of  course,  that  varieties  are  the  same  in 
each  case.  It  has  been  demonstrated  that  market-garden 
crops  of  the  best  quality  are  those  which  are  grown  under 
conditions  which  permit  of  a  continuous  and  rapid  develop- 
ment. Any  delay  in  the  growth  of  a  radish  or  of  lettuce 

283 


284  Fertilizers 

is  largely  responsible  for  the  sharp  taste  and  pungent 
flavor  of  the  former,  and  the  bitterness  and  toughened 
fiber  of  the  latter.  The  same  principles  hold  true  of  early 
table  beets  and  turnips.  The  beets  become  stringy  and 
wiry  in  character,  and  are  less  palatable  if  during  the 
period  of  normal  growth  there  has  been  any  delay.  In 
a  time  during  which  there  has  been  no  progress  the 


Fio.  26.  —  GARDEN  FERTILIZER  SOWER. 

The  garden  fertilizer  sower  has  the  advantage  of  concentrating  plant- 
food  in  the  row.  This  machine  is  very  useful  when  several  small  appli- 
cations of  soluble  constituents  are  made  to  young  plants  during  the 
growing  season,  because  it  places  the  plant-food  within  immediate  reach  of 
the  roots. 

fibrous  portion  of  the  vegetable  is  toughened,  and  exists 
in  too  great  proportion.  In  the  case  of  the  early  tur- 
nip, if  any  delay  in  growth  occurs,  the  quality  is  in- 
jured, and  the  peculiar,  pleasant  flavor,  a  characteristic 
of  the  perfect  vegetable,  is  changed ;  it  becomes  un- 
pleasant. The  unfavorable  conditions  of  growth  seem 
to  cause  more  or  less  reversion  to  the  character  of  the 
original  plant  from  which  the  improved  type  has  been 


Market-Garden  Crops  285 

derived,  mainly  through  selection  and  improved  methods 
of  cultivation. 

All  these  conditions  of  growth  are  not  absolutely  under 
the  control  of  the  grower ;  as,  for  example,  a  lack  of  suffi- 
cient moisture  and  sunshine,  the  latter  of  which  is  cer- 
tainly beyond  his  power  to  control.  But  given  good 
natural  conditions  in  respect  to  soil,  and  a  favorable 
season,  the  one  thing  that  more  than  any  other  controls 
the  yield  and  quality  of  market-garden  products  is  plant- 
food  of  the  right  amount  and  kind.  In  other  words,  in 
crops  of  this  sort,  any  limitation  in  this  respect  usually 
results  in  a  disproportionate  reduction  in  profits.  Only 
under  exceptional  circumstances  is  it  economical  to  depend 
upon  natural  soil  conditions  for  profitable  crops,  however 
favorable  such  conditions  may  be,  because  in  successful 
practice  the  cropping  is  in  the  highest  degree  "intensive/* 
and  even  the  best  soils  are  liable  to  be  deficient  in  some 
essential  feature. 

In  market-gardening,  two  factors  are  essential :  first, 
a  soil  that  is  capable  of  absorbing  and  holding  water, 
without  being  so  compact  and  tight  as  to  prevent  free 
movement  of  water  in  all  directions.  Probably  a  typical 
garden  soil  would  be  a  sandy  loam;  this  kind  of  soil, 
however,  would  be  largely  regarded  as  a  good  place  for 
the  plants  to  grow,  rather  than  as  an  entire  source  of  food 
required.  Hence,  the  second  factor  is  that  the  soil  should 
contain  an  abundant  supply  of  all  kinds  and  forms  of 
plant-food  needed.  This  may  be  accomplished  by  the  use 
of  manures,  preferably  well  rotted,  which  contain  plant- 
food  in  more  or  less  soluble  forms,  but  which  possess,  in 
addition,  decaying  vegetable  matter,  so  important  in  con- 
tributing to  the  physical  character  of  soils,  more  especially 
in  the  matter  of  holding  moisture.  Hence,  any  soil  well 


286  Fertilizers 

adapted  naturally  for  market-gardening  should  either  be 
heavily  manured,  or  should  have  been  subjected  to  green- 
manuring  for  a  sufficient  period  of  time  to  build  it  up  in 
vegetable  matter.  Owing  to  the  cost,  both  in  money  and 
labor,  of  supplying  the  food  requirements  through  the  use 
of  manures  only,  nowadays  resort  is  made  to  commercial 
fertilizers;  these  not  only  supply  the  total  food,  but 
are  capable  of  supplying  them  in  such  forms  as  to  enable 
the  plants  to  absorb  them  at  once.  That  is,  there  is  no 
necessity  for  any  delay,  in  order  that  the  plant-food  con- 
stituents themselves  may  be  made  available.  Fertilizers 
are  therefore  capable  of  supplying  the  needed  require- 
ments when  other  conditions  are  favorable,  and  may  be 
grouped  into  three  classes;  i.e.  general,  specific  and 
basic.  That  is,  a  general  formula  would  be  one  that  is 
not  made  for  any  specific  crop,  but  which  contains  both 
soluble  and  insoluble  forms  of  plant-food,  with  the  idea 
of  building  up  the  soil  in  the  constituents,  rather  than 
meeting  the  special  requirements  of  any  one  crop. 

The  specific  formula  is  one  made  up  for  the  purpose  of 
meeting  a  particular  need  of  the  crop  at  a  particular  time. 
These  will  be  noted  through  the  discussions  of  the  various 
crops.  A  basic  formula  is  one  containing  large  quantities 
of  all  of  the  best  forms  of  plant-food  to  be  used  as  a  base 
for  supplying  market-garden  crops  with  their  general 
needs,  with  the  idea  that  amendments  may  be  made  of 
nitrogen,  or  of  other  constituents,  as  the  conditions  seem 
to  require. 

It  might  seem  from  the  discussion  thus  far  that  for 
these  crops  the  recommendations  as  to  methods  of  fertili- 
zation might  be  briefly  though  fully  expressed  as  follows : 

Apply  a  reasonable  excess  of  all  of  the  essential  fertilizer 
constituents  to  all  of  the  crops.  Nevertheless,  because  of 


Market-Garden  Crops  287 

the  peculiarities  of  growth  of  the  different  plants,  as  well 
as  the  different  objects  of  their  growth,  distinctions  should 
be  made  in  reference  to  the  kinds  and  amounts  of  plant- 
food  applied,  and  these  distinctions  should  be  borne  in 
mind,  in  order  that  the  most  profitable  returns  may  be 
secured.  Market-garden  crops  may,  however,  be  grouped 
according  to  -similarity,  both  in  character  and  object  of 
growth,  and  each  group  fertilized  in  a  similar  manner, 
which  obviates  the  necessity  of  extra  labor  in  the  prepara- 
tion of  fertilizers. 

A  basic  fertilizer  for  market-garden  crops. 

A  good  basic  fertilizer  for  market-garden  crops  may 
consist  of : 

Nitrate  of  soda 250  Ib. 

Ammonium  sulphate 100  Ib. 

Dried  blood 150  Ib. 

Ground  fish 100  Ib. 

Acid  phosphate,  16%  A.P.A 1000  Ib. 

Sulfate  of  potash 400  Ib. 

A  mixture  of  these  materials  of  standard  quality  would 
show  an  average  composition  of  4  per  cent  nitrogen,  8  per 
cent  phosphoric  acid  and  10  per  cent  potash.  Such  a 
mixture  is  an  excellent  basic  formula  for  such  crops  as 
asparagus,  cucumbers,  onions,  cabbage,  cauliflower,  celery, 
eggplant,  melons,  peppers,  squashes  and  the  like,  but  any 
mixture  of  the  composition  4-8-10  which  supplies  the 
plant-food  constituents  in  good  forms  may  be  used  as  a 
basic  formula  for  all  market-garden  crops,  leaving  the 
specific  needs  of  the  different  plants  to  be  met  by  top- 
dressings,  or  applications  of  the  other  constituents.  The 
fertilizer  ingredients,  nitrogen  and  phosphoric  acid,  should 
preferably  consist  of  the  different  forms,  rather  than  to 


288  Fertilizers 

be  all  of  one  form,  though  the  cost  of  the  element  will 
naturally  regulate  this  point  to  some  extent.  That  is,  a 
part  of  the  nitrogen  should  be  nitrate  or  ammonia,  and  a 
part  organic;  a  part  of  the  phosphoric  acid  should  be 
soluble  (from  superphosphates),  and  a  part  insoluble  (from 
ground  bone,  tankage  or  natural  phosphates).  The  solu- 


FIG.  27.  —  GARDEN  FERTILIZER  SOWER  WITH  HOE  TO  WORK 
FERTILIZER  INTO  SURFACE  SOIL. 

ble  portions  of  both  nitrogen  and  phosphoric  acid  con- 
tribute to  the  immediate  needs  of  the  plant,  and  the  less 
soluble  to  its  continuous  and  steady  growth,  and  to  the 
potential  fertility  of  the  soil. 

The  different  kinds  of  vegetables. 

As  previously  stated,  distinctions  should  be  made  in 
reference  to  the  kinds  and  amounts  of  plant-food  applied 
to  the  many  different  vegetables.  It  is  impossible  in  a 
discussion  of  this  nature  to  give  specific  directions  of  the 
details  of  fertilization  of  each  vegetable;  hence,  the  dis- 


Market-Garden  Crops  289 

cussion  following  will  give  consideration  to  the  various 
groups  of  edible  plants  as  outlined  by  L.  H.  Bailey,  and 
as  much  detail  concerning  each  plant  as  is  practicable. 
This  grouping  is  an  excellent  one  because  it  is  based  upon 
the  object  of  growth,  which  is  an  important  factor  in  the 
cultural  methods  and  fertilization  of  the  various  vege- 
tables. 

ROOT  CROPS 
Beets  and  turnips. 

The  early  table  beet  and  the  early  turnip  are  very  im- 
portant market-garden  crops.  Wherever  grown,  whether 
in  the  South  for  the  northern  market,  or  in  the  middle 
states  for  the  near-by  market,  earliness  is  a  primary  con- 
sideration; and  the  earliness  of  the  crop  is  determined 
largely  by  the  amount  and  availability  of  the  nitrogen 
and  phosphoric  acid  applied.  These  are  the  two  elements 
which,  more  than  any  others,  modify  and  dominate  the 
growth  of  these  plants,  and  contribute  to  their  profitable 
production  as  early  market-garden  crops.  In  the  case  of 
early  turnips  particularly,  a  difference  of  two  or  three 
days  in  the  beginning  of  the  harvest  will  often  determine 
the  profit  or  loss  upon  the  crop.  The  experience  of  many 
growers  confirms  the  view  that  for  no  other  crop  is  the 
necessity  for  right  fertilization  more  important.  Since 
the  early  growth  of  these  crops  takes  place  before  active 
nitrification  begins  in  the  soil,  dependence  for  this  element 
must  be  placed  upon  the  nitrogen  applied,  and  it  is  desir- 
able not  only  that  the  soils  should  be  well  supplied  at  the 
time  of  planting  with  all  of  the  constituents,  but  that  fre- 
quent top-dressings  of  the  soluble  nitrate  shall  be  made. 
Top-dressings  are  recommended  because  the  application 
of  a  sufficient  amount  of  the  nitrogen  in  this  form  at  the 


290  Fertilizers 

time  of  seeding  might  result  in  its  considerable  loss,  since 
at  this  season  rains  often  occur  which  are  frequently  so 
heavy  as  to  cause  a  leaching  of  the  nitrates  into  the  drains 
or  into  the  lower  layers,  and  thus  prevent  the  continuous 
feeding  of  the  plant,  and  a  consequent  delay  in  growth. 

An  application,  therefore,  of  from  1000  to  1500  pounds 
of  a  high-grade  fertilizer,  one  of  the  composition  of  the 
basic  fertilizer  already  suggested  (p.  287),  is  frequently 
employed  at  the  tune  of  seeding,  followed  by  a  top- 
dressing  of  from  50  to  100  pounds  of  nitrate  of  soda  to 
the  acre  once  every  week  or  ten  days,  for  at  least  three  or 
four  weeks  after  the  plants  have  well  started.  It  will 
meet  the  requirements  for  added  fertility.  Such  a  prac- 
tice, under  average  seasonal  conditions,  insures  a  con- 
tinuous and  rapid  growth,  and  obviates  to  some  extent 
the  dangers  liable  to  follow  from  too  much  rain  or  from 
drought.  The  frequent  applications  prevent  losses  from 
leaching  if  heavy  rains  follow,  and,  except  in  case  of  exces- 
sive and  prolonged  drought,  the  nitrate  remains  in  solu- 
tion, and  is  ready  to  be  immediately  absorbed  by  the 
plant.  The  advantage  of  earliness  which  is  gained  by  the 
use  of  apparently  excessive  amounts  of  nitrogen  is  two- 
fold :  a  higher  price  is  received  for  the  product,  and  the 
cost  of  labor  required  for  each  unit  of  income  is  less. 
Quite  as  large  yields  may  be  obtained  by  smaller  dressings, 
but  the  net  income  is  reduced  as  the  time  necessary  for 
the  growth  of  a  marketable  beet  or  turnip  is  increased. 
See  also  Chapter  XIV,  in  reference  to  this  subject. 

Carrots. 

The  food  requirements  of  carrots  are  very  great,  a 
yield  of  15  tons  an  acre  will  remove  48  pounds  of  nitrogen, 
27  of  phosphoric  acid  and  153  of  potash.  For  high-grade 


Market-Garden  Crops  291 

edible  carrots,  no  less  than  1000  pounds  of  a  mixture 
carrying  4  per  cent  of  nitrogen,  4  per  cent  of  phosphoric 
acid  and  12  per  cent  of  potash  should  be  used.  In  case 
the  season  is  favorable  for  rapid  development,  top-dressings 
of  nitrate  of  soda  are  very  profitable. 

The  other  crops  of  this  group,  including  celeriac,  chicory, 
horseradish,  parsnip,  radish  and  salsify,  may  be  fertilized 
with  liberal  applications  of  the  basic  fertilizer.  It  should 
be  remembered  in  connection  with  each  that  the  crops  of 
this  group  require  large  quantities  of  potash,  and  that 
phosphoric  acid  is  relatively  much  less  important. 

BULB  CROPS 

This  group  includes  chive,  garlic,  leek,  shallot  and 
onion.  Because  the  onion  is  the  most  important  it  is 
discussed  liberally.  The  fertilization  of  the  other  crops 
may  be  the  same. 

The  growing  of  onions,  either  from  seed  or  from  sets, 
and  the  growing  of  sets  according  to  "intensive"  systems 
of  practice,  requires  a  soil  of  a  suitable  physical  character 
well  supplied  with  all  of  the  essential  constituents  of  fer- 
tility. The  minerals  should  be  supplied  in  abundance  by 
superphosphates  and  potash  salts,  while  the  nitrogen 
should  be  supplied  in  the  most  active  forms,  and  in  even 
larger  amounts  than  for  many  other  crops.  The  present 
systems  of  growing  these  crops  require  that  the  sets  shall 
be  planted  and  the  seed  sown  more  thickly  than  was 
formerly  believed  to  be  desirable,  which  permits  of  a 
larger  yield  to  the  unit  of  area,  though  it  requires  better 
culture  and  a  very  much  larger  quantity  of  available  plant- 
food  than  was  the  case  under  the  former  rather  "exten- 
sive" systems  of  culture.  Except  in  the  case  of  very 


292  Fertilizers 

early  onion  crops,  immediate  rapid  growth  after  setting 
is  not  so  essential  as  in  the  case  of  many  other  market- 
garden  crops,  and  in  the  growing  of  onion  sets,  when  the 
soil  is  richly  provided  with  food,  great  care  in  manage- 
ment is  necessary  in  order  to  secure  a  development  of  bulb 
that  shall  not  be  too  large,  in  which  case  the  salable 
quality  of  sets  will  be  reduced.  Hence,  to  avoid  this, 
the  seed  should  be  spread  thickly,  in  rows  about  3  inches 
wide,  and  the  cultivable  portion  between  the  rows  about 
8  inches  wide.  With  so  large  a  portion  of  the  surface  area 
occupied  with  the  crop,  the  danger  of  too  large  develop- 
ment from  heavy  fertilization  is  greatly  reduced. 

In  growing  scallions,  the  soil  should  not  only  be  richly 
provided  with  minerals  and  organic  forms  of  nitrogen,  as 
in  the  case  of  the  other,  but  should  be  supplied  early  with 
soluble  nitrate,  in  order  to  meet  the  demands  for  this  ele- 
ment before  it  is  available  from  soil  sources.  In  the  grow- 
ing of  crops  which  require  so  much  hand  labor  as  onions, 
fertilizers  are  also  preferable  to  yard  manures,  because 
they  are  free  from  weed  seed.  Further,  fertilizers  do  not 
contribute  toward  the  development  of  insects  or  diseases, 
as  is  sometimes  the  case  with  manures,  particularly  with 
the  product  derived  from  city  stables. 

A  good  general  fertilizer  for  onion  sets  for  soils  of  fair 
fertility  may  consist  of  about  50  pounds  to  the  acre  of 
nitrogen  in  organic  forms,  as  dried  blood,  cotton-seed  meal 
or  tankage,  60  of  phosphoric  acid,  which  may  be  partly 
in  organic  forms,  as  bone  or  tankage,  and  100  of  actual 
potash,  derived  from  a  muriate.  The  application  of  a 
formula  containing  — 

Nitrogen 5% 

Phosphoric  acid 6% 

Potash 10% 


Market-Garden  Crops  293 

at  the  rate  of  1000  pounds  to  the  acre,  and  well  worked 
into  the  soil  previous  to  planting,  would  furnish  these 
amounts,  and  this  application,  together  with  a  top- 
dressing  of  from  75  to  100  pounds  to  the  acre  of  nitrate 
of  soda,  or  60  to  75  pounds  of  sulfate  of  ammonia,  two  or 
three  times  at  intervals  of  about  three  weeks,  the  first 
after  the  crops  have  well  started,  would  provide  not  only 
an  abundance  of  food  of  the  right  sort,  but  the  nitrogen 
when  needed,  without  danger  of  loss. 

If  the  soil  has  been  well  dressed  with  a  general  fertilizer, 
as  above  described,  the  scallions  should  receive  a  dress- 
ing of  nitrate  just  as  soon  as  growth  begins  in  the  spring, 
as  rapid  and  early  growth  at  this  season  will,  other  con- 
ditions being  equal,  depend  upon  the  supply  of  available 
nitrogen,  and  nitrogen  in  available  forms  is  not  usually 
present  in  the  soil  in  sufficient  quantities  so  early  in  the 
season. 

COLE  CEOPS 

Broccoli,  brussel  sprouts,  cabbage  (see  Fig.  28,  Plate 
XIV),  collard,  cauliflower  and  kale  are  all  large-leaved 
plants  and  voracious  feeders,  and  are  specifically  benefited 
by  large  applications  of  nitrogen  and  of  phosphoric  acid. 
Heavy  applications  of  the  basic  fertilizer,  which  is  excel- 
lent, should  be  supplemented  upon  good  soils  with  addi- 
tions of  nitrogen  and  phosphoric  acid,  and  upon  light 
soils,  potash  may  also  be  added.  Notwithstanding  the 
fact  that  these  crops  are  particularly  benefited  by  nitro- 
gen, the  character  of  the  edible  portion  or  head  of  the 
different  plants  is  very  largely  influenced  by  the  nature 
of  the  growth.  Too  rapid  an  early  growth,  due  to  an 
excess  of  nitrogen,  frequently  results  in  an  abnormal 
development  of  leaf,  which  is  not  accompanied  by  a 


294  Fertilizers 

proper  formation  of  the  head ;  hence  a  part  of  the  nitro- 
gen essential  for  the  growth  of  the  plant  after  the 
head  has  begun  to  form  should  be  applied  at  this  time 
in  an  immediately  available  form,  and  a  part  in  forms 
which  will  gradually  feed  the  plant.  A  good  method  of 
fertilization,  in  addition  to  the  application  of  from  1000 
to  1500  pounds  to  the  acre  of  the  basic  fertilizer,  there- 
fore, may  consist  of  a  top-dressing  of  100  pounds  of  nitrate 
of  soda  and  200  of  superphosphate  to  the  acre,  after  the 
plants  have  begun  to  make  growth  after  transplanting. 
After  the  heads  begin  to  form,  another  top-dressing  of 
200  pounds  of  nitrate  of  soda  may  be  applied,  which  will 
contribute  toward  a  rapid  and  continuous  growth  of  head, 
provided  an  abundance  of  the  minerals  is  present,  as 
already  indicated. 

A  number  of  crops  belonging  to  this  group  of  plants 
require,  in  addition  to  a  sufficient  supply  of  plant-food, 
peculiar  climatic  conditions  for  their  best  crop  develop- 
ment. Cauliflower,  particularly,  not  only  seems  to  be  so 
influenced,  but  great  skill  and  experience  are  required  on 
the  part  of  the  grower.  It  must  be  remembered  that 
while  proper  fertilization  is  essential,  it  is  only  one  of  the 
primary  conditions  of  successful  culture. 

POT  HERBS 

Beet,  chard,  dandelion,  mustard,  sea  kale  and  spinach, 
grown  for  their  tops  or  the  edible  portion  of  the  leaf,  are 
encouraged  in  their  development  by  an  abundance  of 
available  nitrogen,  as  this  element  is  the  one  which  con- 
tributes more  than  any  other  to  formation  of  leaf.  Abun- 
dant growth  of  the  right  sort  is  only  accomplished  when  it 
is  present  in  such  quantities  and  in  such  forms  as  to  con- 


PLATE  XIV.  — Cabbage  and  Watermelons. 


FIG.  28.  —  CABBAGE  HEAVILY  FERTILIZED,  FREEHOLD,  NEW  JERSEY. 


FIG.  29. —  WATERMELONS,  PEPPERS  AND  CORN  FERTILIZED  WITH  BASIC 
FERTILIZER,  CLARKSBORO,  NEW  JERSEY. 


Market-Garden  Crops  295 

tinuously  supply  the  plant  with  its  needs.  Reasonably 
heavy  dressings  of  the  basic  formula,  1000  pounds  to  the 
acre,  or  over,  at  time  of  planting,  should  be  followed  by 
a  top-dressing  of  100  pounds  to  the  acre  of  nitrate  of  soda 
after  the  plants  are  well  started.  The  late  fall  and  winter 
growth  of  spinach  is  especially  benefited  by  the  application 
of  nitrates. 

SALAD  CROPS 

Celery. 

Celery  is  another  plant  that  luxuriates  in  a  soil  rich  in 
vegetable  matter,  though  the  peculiar  advantage  of  this 
natural  condition  of  soil  may  be  largely  met  where  it  is 
possible  to  secure  an  abundance  of  water  and  plant-food 
in  soluble  forms.  In  the  absence  of  an  abundance  of 
water,  even  the  best  judgment  in  application  of  fertilizers 
wrill  not  result  in  satisfactory  growth.  A  heavy  applica- 
tion of  the  basic  mixture  —  a  ton  to  the  acre,  used  at  time 
of  setting  the  plants  —  may  be  followed  with  advantage 
by  frequent  and  reasonably  heavy  top-dressings  of  nitrate 
of  soda,  100  pounds  to  the  acre  or  more,  and  well  worked 
into  the  soil.  This  abundance  of  soluble  nitrogen  will 
contribute  toward  that  rapidity  of  growth  which  is  accom- 
panied by  the  peculiar  crispness  and  sweetness  that  gives 
edible  quality  to  this  vegetable.  In  the  absence  of  suffi- 
cient water  and  food,  not  only  is  the  growth  of  the  plant 
retarded,  but  the  quality  of  that  obtained  is  materially 
influenced,  since  the  development  of  the  bitter  flavor  and 
fibrous  character  that  frequently  cause  a  reduced  consump- 
tion of  this  valuable  plant  is  apparently  encouraged. 

What  has  already  been  said  concerning  this  vegetable 
is  true  of  a  number  of  others :  the  main  thing  is  to  see  to 
it  that  such  an  abundance  of  available  food  of  the  right 


296  Fertilizers 

kind  is  provided  as  to  make  possible  a  rapid  growth  when 
other  conditions  are  favorable.  This  is  one  of  the  pri- 
mary necessities,  if  a  high  yield  of  good  quality  product  is 
obtained. 

Lettuce. 

There  is  no  market-garden  crop  which  derives  greater 
benefit  from  heavy  applications  of  stable  manure  than 
lettuce.  Besides  increasing  the  amount  of  plant-food  in 
the  soil,  it  helps  to  bring  about  that  mechanical  condition 
of  soil  so  important  in  successful  lettuce-production. 
Crispness  and  high  quality  are  essential  to  make  lettuce 
readily  marketable,  hence  an  abundance  of  all  the  con- 
stituents of  plant-food  in  available  form  must  be  present 
in  the  soil.  An  application  of  no  less  than  1000  pounds 
of  the  basic  mixture  should  be  used  at  the  time  of  plant- 
ing, supplemented  with  dressings  of  nitrate  of  soda  at  the 
rate  100  to  150  pounds  to  the  acre  at  intervals  of  ten  to 
fifteen  days  after  the  plants  are  of  fair  size. 

The  fertilization  of  corn  salad,  cress,  endive  and  parsley, 
the  other  plants  of  this  group,  may  be  essentially  the 
same  as  that  suggested  for  lettuce.  They  are  all  grown 
for  the  leaves  and  require  fertile  soils  liberally  supplied 
with  all  the  constituents  of  plant-food  in  available  forms. 

PULSE  CROPS 

Peas  and  beans  of  the  various  kinds  and  varieties  belong 
to  the  legume  family,  and  possess  the  power  of  acquiring 
nitrogen  from  the  air;  they  are,  therefore,  ordinarily 
placed  in  a  separate  class  in  respect  to  their  fertiliza- 
tion with  nitrogen.  When  they  are  grown  as  market- 
garden  crops,  however,  it  is  frequently  the  wiser  economy 


Market-Garden  Crops  297 

to  apply  nitrogen,  particularly  if  they  are  raised  upon 
land  which  has  not  been  previously  planted  with  these 
crops,  and  thus  may  not  possess  the  specific  nitrogen- 
gathering  bacteria:  because  it  is  imperative  that  the 
plants  should  not  only  have  an  abundance  of  all  of  the 
food  constituents,  but  that  their  food  should  be  such  as 
to  cause  as  long  a  cropping  period  as  possible,  and  nitro- 
gen will  contribute  to  this  end.  Hence,  in  the  fertiliza- 
tion of  these  crops,  while  the  minerals  are  the  primary 
constituents  needed,  nitrogen  should  also  be  applied,  and 
it  should  preferably  be  in  the  organic  forms,  which  en- 
courage a  longer  period  of  growth,  rather  than  in  the 
single,  active-form  nitrate,  more  generally  recommended 
for  the  quick-growing  market-garden  crops,  because  its 
complete  solubility  and  immediate  availability  encourage 
a  rapid  growth  and  short  period  of  development.  The 
basic  fertilizer  recommended,  if  applied  at  the  rate  of  500 
to  600  pounds  to  the  acre,  will  usually  furnish  sufficient 
nitrogen,  and  may,  if  necessary,  be  supplemented  by  the 
application  of  amounts  of  superphosphate  and  potash 
salts  which  will  add  from  20  to  30  pounds  of  phosphoric 
acid,  and  60  to  75  of  potash. 


SOLANACEOUS  CROPS 

Eggplant. 

The  eggplant  belongs  to  the  same  botanical  family  as 
the  potato,  and  while  specifically  benefited  by  the  fertiliz- 
ers recommended  for  that  crop,  is  improved  by  the 
further  addition  of  nitrogen,  which  stimulates  an  early 
leaf  growth.  Good  organic  forms  are  quite  as  useful  as 
the  nitrates  or  ammonia,  unless  the  latter  are  used  fre- 
quently as  top-dressings.  (See  page  239.) 


298  Fertilizers 

Peppers.     (See  Fig.  29,  Plate  XIV.) 

The  same  treatment  may  be  accorded  peppers  when 
grown  under  garden  conditions  as  previously  suggested  on 
page  257,  except  that  a  more  liberal  supply  of  plant-food 
may  be  made.  It  should  be  remembered,  especially  in 
connection  with  liberal  applications  of  stable  manure,  that 
an  abundant  supply  of  minerals  should  be  present  in  the 
soil  to  encourage  continuous  growth  and  fruiting.  After 
the  plants  are  well  established,  an  abundance  of  available 
nitrogen  should  be  avoided. 

Tomatoes. 

The  fertilization  of  both  early  and  late  tomatoes  is 
discussed  in  Chapter  XIII,  and  it  seems  unnecessary 
to  add  to  that  discussion  here  except  to  emphasize  the 
importance  of  a  liberal  supply  of  the  mineral  elements 
—  phosphoric  acid  and  potash.  Many  growers  have 
found  the  Wagner  system  of  fertilization,  which  is  based 
upon  the  necessity  of  an  abundant  supply  of  minerals 
and  fractional  applications  of  available  nitrogen,  a  good 
practice.  (For  Wagner  System,  see  page  205.)  On  the 
other  hand,  there  are  many  growers  who  prefer  to  make  a 
single  application  in  large  amount  of  a  fertilizer  deriving 
its  nitrogen  from  a  number  of  sources.  A  mixture  very 
generally  used  in  New  Jersey  is  made  of  the  following 
materials : 

Nitrate  of  soda 100  Ib. 

Sulfate  of  ammonia 100  Ib. 

Dried  blood,  16%  AM 100  Ib. 

Ground  fish       100  Ib. 

Ground  bone 100  Ib. 

Acid  phosphate 1100  Ib. 

Sulfate  of  potash 400  Ib. 


Market-Garden  Crops  299 

This  is  undoubtedly  an  excellent  mixture  which  may  be 
used  with  safety  in  almost  any  quantity.  The  usual 
practice  is  to  use  from  1000  to  1200  pounds  to  the  acre. 
Many  farmers  claim  that  the  sulfate  of  ammonia  causes 
some  injury  to  the  tomato  and  prefer  to  double  the  quan- 
tities of  blood  and  fish  used.  Whether  there  is  any 
ground  for  this  claim  has  never  been  definitely  deter- 
mined, but  it  is  known  that  sulfate  of  ammonia  leaves  a 
large  residue  of  acid  in  the  soil. 

VINE  CROPS 

Cucumbers,  watermelons  (see  Fig.  29,  Plate  XIV),  musk- 
melons,  pumpkins  and  squashes  belong  to  one  botanical 
group  of  plants,  and  are  usually  adapted  for  similar 
climatic  and  soil  conditions,  though  watermelons  and 
muskmelons  of  good  quality  are  successfully  grown  only 
upon  light,  warm,  sandy  soils.  The  pumpkins,  cucum- 
bers and  squashes  may  be  readily  grown  to  perfection 
upon  the  colder  and  more  compact  clayey  soils.  All 
of  these  crops  require  an  abundance  of  vegetable  matter 
in  the  soil,  in  order  to  make  their  best  growth.  Hence, 
upon  soils  deficient  in  this  respect,  manures  should 
be  applied  which  are  rich  in  vegetable  matter.  Com- 
posts in  the  hill  have  proved  of  especial  advantage, 
as  they  seem  to  encourage  an  immediate  feeding,  and 
prevent  delay  in  early  growth.  In  the  best  growth  of 
these  plants  it  is  also  necessary  that  the  mineral  ele- 
ments shall  be  available,  and  that  the  nitrogen  shall  be 
of  such  a  character  as  to  encourage  a  continuous  rather 
than  a  quick  growth  of  vine.  That  is,  unless  the  quick- 
acting  nitrates  are  applied  very  frequently,  they  are  less 
desirable  than  organic  forms  of  nitrogen.  Hence,  with  the 


300  Fertilizers 

usual  broadcast  application  of  the  basic  mixture  at  the 
time  of  planting,  together  with  a  compost  in  the  hill, 
further  applications  of  organic  nitrogen  should  be  made, 
its  character  to  be  such  as  to  promise  a  relatively  rapid 
change  into  nitrate.  The  basic  mixture  may  be  ree'n- 
forced  by  any  one  of  the  following  materials :  200  to  300 
pounds  to  the  acre  of  cotton-seed  meal,  100  to  200  of 
dried  blood  or  300  to  400  pounds  of  fine-ground  tankage 
or  ground  fish.  Any  organic  substance  whose  greater  part 
will  decay  in  one  season  will  generally  give  better  results 
than  the  nitrate,  unless  the  latter  is  applied  in  frequent 
small  top-dressings,  because  organic  forms  of  nitrogen 
provide  for  a  continuous  growth  of  vine  and  fruit,  while 
too  great  an  abundance  of  immediately  available  nitrogen 
as  nitrate  is  liable  to  cause  too  rapid  and  large  growth  of 
fruit  of  poor  quality.  This  does  not  apply  in  the  case  of 
cucumbers  for  pickling,  where  a  large  setting  of  immature 
fruits  is  desired.  In  this  case,  nitrogen  in  the  form  of  a 
nitrate,  if  properly  applied,  will  contribute  to  a  large 
setting  and  a  rapid  growth  of  the  fruits. 

MISCELLANEOUS  CROPS 


Asparagus  is  one  of  the  very  important  vegetable  crops, 
and  perhaps  no  other  renders  so  profitable  a  return  for 
proper  manuring  and  fertilizing.  It  differs  from  the 
majority  of  the  others  in  two  essential  particulars.  First, 
it  is  a  perennial,  the  length  of  life  of  a  bed  depending 
largely  upon  the  treatment;  and  second,  only  one  crop 
can  be  obtained  in  a  season  —  it  occupies  the  land  to  the 
exclusion  of  other  crops.  Hence,  special  efforts  should  be 
made  to  obtain  as  large  a  crop  as  the  conditions  of  season 


Market-Garden  Craps  301 

and  climate  will  permit.  With  this  plant  the  yield  and 
market  quality  of  the  crops  depend  upon  the  number  and 
size  of  the  shoots.  In  respect  to  quality,  the  demands  of 
the  different  markets  vary.  Some  of  them  require  that 
the  shoots  shall  be  bleached  and  so  cut  as  to  present  only 
a  green  tip,  the  remainder  being  perfectly  white,  while 
others  demand  that  the  shoot  shall  be  green.  But  in  both 
cases,  the  size  of  the  shoot  determines  salability,  and  the 
size  is  largely  measured  by  the  methods  observed  in  feed- 
ing the  plant  when  other  conditions  are  favorable;  that 
is,  if  not  injured  by  disease  or  insects.  Small,  spindling 
shoots  usually  indicate  that  the  crop  has  not  been  well 
cared  for,  or  that  the  plant  has  been  imperfectly  nourished. 

The  root  is  enlarged  and  invigorated  by  the  character 
of  the  growth  of  the  tops,  or  summer  growth  of  the  plant 
after  cutting  is  finished,  and  it  is  obvious  that  the  manur- 
ing should  be  such  as  to  encourage  not  only  a  rapid  growth 
of  shoots  early,  but  a  large  and  vigorous  growth  of  tops 
later,  which  assists  the  growth  of  the  roots  in  which  energy 
is  stored  up  for  the  production  of  the  crop  in  the  following 
year.  Hence,  not  only  the  character  but  the  method  of 
fertilization  is  important,  and  it  differs  from  that  recom- 
mended for  those  plants  which  grow  from  the  seed  in  one 
season  and  which  must  depend  upon  what  they  are  able 
to  acquire  during  their  short  period  of  growth. 

It  was  formerly  believed  that  one  of  the  most  impor- 
tant ingredients  of  manures  for  the  asparagus  plant  was 
common  salt,  and  that  in  any  fertilization  this  substance 
should  occupy  a  prominent  part.  Experience  has  shown, 
however,  that  while  salt  may  not  be  harmful,  there  is  no 
real  fertility  value  in  it.  The  crop  may  be  profitably 
grown  without  its  application,  though  it  does  no  harm, 
and  there  is  no  objection  to  its  use  except  on  the  ground 


302  Fertilizers 

that  it  adds  no  essential  fertility  element,  and  its  indirect 
benefit  may  be  obtained  more  cheaply  by  the  use  of  other 
materials,  which  contain  salt  as  a  normal  ingredient,  — 
for  example,  kainit,  the  crude  potash  salt,  which  is  one- 
third  salt,  though  its  market  price  is  based  solely  upon  its 
potash  content. 

Fertilizers  which  have  been  found  very  useful  for 
asparagus  are  those  which  contain  food  both  in  immedi- 
ately available  and  in  gradually  available  forms.  During 
the  early  growing  season,  the  available  food  may  be 
appropriated  rapidly  enough  to  cause  an  increase  in  the 
yield  of  shoots  of  that  year;  and  inasmuch  as  the  plant 
continues  to  grow  until  winter,  the  food  that  becomes 
gradually  available  is  appropriated  later,  and  contributes 
to  the  strength  and  vigor  of  the  roots  upon  which  the  next 
year's  crop  depends.  Furthermore,  because  the  crop  is 
gathered  from  the  early  shoots,  which  are  continuously 
removed  for  from  one  to  two  months,  the  root  is  continu- 
ously drained  of  its  stored-up  material,  and  at  the  end  of 
the  cutting  season  it  has  been  very  much  reduced  in 
vitality ;  wherefore  it  is  particularly  desirable  that  avail- 
able food  be  applied  at  this  time  also,  in  order  to  encour- 
age a  rapid  and  vigorous  growth  of  the  top,  which  aids  in 
the  storing  up  of  food  in  the  root.  A  fertilizer  containing — 

Nitrogen 4% 

Phosphoric  acid 8% 

Potash 10% 

the  nitrogen  to  be  drawn  from  both  soluble  and  organic 
sources,  and  the  phosphoric  acid  from  both  superphosphate 
and  ground  bone,  or  tankage,  and  the  potash  from  muriate, 
may  be  applied  at  the  rate  of  1000  to  1500  pounds  to  the 
acre,  and  thoroughly  worked  into  the  soil  at  the  time  of 


Market-Garden  Crops  303 

setting  the  crowns,  or  even  in  greater  amounts  from  year 
to  year,  preferably  early  in  the  spring,  in  order  that  the 
plant  may  have  the  whole  season  for  the  appropriation  of 
the  food. 

The  specific  fertilizer,  in  addition,  should  contain  im- 
mediately available  forms  of  food,  and  should  be  applied 
preferably  immediately  after  or  during  the  latter  period 
of  the  cutting,  in  order  to  feed  at  once,  and  thus  stimulate 
and  strengthen  the  plant  in  its  condition  of  lowered  vitality, 
due  to  the  continuous  and  large  removal  of  the  shoots. 
This  application  should  also  be  liberal,  since,  as  already 
indicated,  limitations  at  this  time  may  result  in  a  greatly 
decreased  yield  and  a  poorer  quality  of  product  the  next 
year,  and  hence  a  reduction  in  profit.  The  best  growers 
.  apply,  in  addition  to  the  fertilizer  recommended,  and  after 
cutting,  not  less  than  250  pounds  of  nitrate  of  soda,  300 
of  superphosphate,  and  muriate  of  potash,  or  kainit, 
equivalent  to  100  pounds  of  actual  potash. 

These  recommendations  as  to  the  amounts  of  fertilizers 
may  seem  rather  large  to  those  who  have  been  accustomed 
to  light  applications,  but  they  are  the  minimum  rather 
than  the  maximum  amounts,  as  many  growers  have  learned 
that  the  extra  amounts  applied  are  preferable  to  the 
smaller  amounts,  contributing  not  only  to  the  length  of 
life  of  the  plant,  but  also  to  the  total  yield  and  size  of  the 
shoots,  as  well  as  to  their  edible  quality,  which  is  measured 
by  their  succulence  and  flavor. 

These  suggestions  as  to  fertilizers  are  for  conditions 
where  large  amounts  of  organic  or  natural  manures  are 
not  readily  obtainable.  When  these  are  used,  they  may 
serve  instead  of  the  basic  fertilizer,  but  cannot  well  sub- 
stitute the  special  applications  of  artificial  fertilizers  made 
after  cutting  is  finished. 


304  Fertilizers 

The  fertilization  suggested  above  may  be  used  with 
absolute  safety  and  excellent  results  may  be  obtained,  but 
it  should  be  kept  in  mind  that  investigators  and  growers 
differ  greatly  regarding  the  fertilizing  of  asparagus. 
While  it  is  conceded  that  nitrogen  is  the  most  important 
element,  the  form  and  time  of  application  are  still  matters 
of  contention.  As  an  alternative  method,  Watts  makes 
the  following  suggestions :  "If  seeds  and  plants  have  been 
selected  intelligently  and  all  cultural  conditions  are  favor- 
able, the  following  treatment  should  give  good  results: 
Apply  10  to  15  tons  of  fine  manure  early  in  spring,  or 
probably  with  as  much  benefit  immediately  after  the 
cutting  season ;  one  and  one-half  tons  of  a  4-8-10  mixture, 
half  applied  in  early  spring,  and  half  immediately  after 
the  first  cutting ;  150  pounds  of  nitrate  of  soda  by  broad- 
casting as  soon  as  growth  begins  in  the  spring ;  150  pounds 
of  nitrate  of  soda  when  the  cutting  season  is  half  over; 
150  pounds  of  nitrate  of  soda  at  the  close  of  the  cutting 
season  and  the  same  quantity  one  month  later." 

Rhubarb. 

Rhubarb  is  a  crop  somewhat  similar  to  asparagus,  in 
that  it  is  a  perennial,  and  that  the  best  fertilization  is  one 
which  not  only  provides  food  for  the  growth  of  the  imme- 
diate crop,  but  which  encourages  the  growth  of  top  after 
the  regular  crop  is  harvested,  and  thus  restores  the  vitality 
of  the  plant  —  which  has  been  weakened  by  the  continu- 
ous removal  of  the  stalk  and  leaf  —  and  enables  it  to 
store  up  energy  for  the  subsequent  crop.  An  annual 
application  of  1500  pounds  of  the  basic  formula  (p.  287) 
early  in  the  spring,  preferably  plowed  in,  may  be  followed 
with  advantage  by  a  top-dressing  of  150  pounds  to  the 
acre  of  nitrate  of  soda  in  about  two  weeks  after  harvesting 


Market-Garden  Crops  305 

has  begun,  and  a  similar  dressing  after  harvesting  has 
ceased.  These  dressings  should  be  cultivated  into  the 
soil,  unless  immediately  followed  by  rain,  which  will  dis- 
tribute the  salt  into  the  lower  layers  of  soil.  Plants  of 
this  sort,  from  which  only  one  crop  can  be  secured,  should 
be  stimulated  to  the  largest  possible  production. 

Sweet  corn. 

In  the  case  of  sweet  corn,  the  early  crop  is  usually  the 
most  profitable.  The  recommendations  that  are  made  for 
the  fertilization  of  the  field  crop  do  not  apply  to  this,  be- 
cause the  object  is  not  the  matured  crop,  which  makes  its 
greatest  development  in  July  and  August,  the  most  favor- 
able season  of  growth,  but  the  early  green  product,  which 
is  often  harvested  before  the  field  crop  has  fairly  begun  to 
grow.  This  early  and  rapid  growth,  therefore,  cannot  be 
attained  by  methods  of  fertilization  suitable  for  the  field 
crop  (Chapters  XII  and  XIV) .  It  can  be  accomplished  only 
when  an  abundance  of  the  mineral  foods  is  present,  and 
when  the  nitrogen  is  in  part,  at  least,  in  forms  which  may 
be  directly  absorbed,  as  much  growth  must  be  made  pre- 
vious to  the  time  that  nitrification  takes  place  in  the  soil. 

The  large  quantity  of  well-rotted  manure  which,  until 
recently,  was  practically  the  only  manure  used  for  this 
crop,  while  extremely  valuable,  can  be  in  part  substituted 
by  a  liberal  dressing  of  the  minerals,  phosphoric  acid  and 
potash,  and  further  supplemented  by  nitrogen  in  readily 
available  forms.  The  use  of  1000  to  1200  pounds  of  a 
mixture  composed  of  the  following  ingredients 

Nitrate  of  soda 200  Ib. 

Dried  blood,  16%  AM 100  Ib. 

Ground  fish 200  Ib. 

Acid  phosphate 1200  Ib. 

Muriate  of  potash 300  Ib. 


306  Fertilizers 

may  be  practiced  with  advantage.  Where  cotton-seed 
meal  may  be  secured  at  a  reasonable  price,  it  may  be  used 
instead  of  fish.  This  mixture  should  be  supplemented  by 
top-dressings  of  nitrate  of  soda  whenever  the  plants  show 
that  more  nitrogen  is  needed.  Care  should  be  taken  to 
work  the  nitrate  of  soda  into  the  soil  immediately  after 
the  application  is  made.  The  basic  formula  (page  287) 
used  at  the  rate  of  800  to  1000  pounds  to  the  acre  and 
supplemented  by  top-dressings  of  nitrate  of  soda  may  be 
used  with  good  results  if  more  convenient. 

Okra. 

The  production  of  okra  is  increasing,  especially  in  the 
canning  sections,  where  it  is  grown  extensively  and  the 
pods  prepared  for  soup.  It  requires  a  warm  and  fertile 
soil.  Because  okra  is  grown  for  pods  while  still  green  and 
which  must  be  crisp  and  tender,  an  early  and  vigorous 
growth  of  leaf  and  stem  is  required.  The  best  practice  is 
to  use  no  less  than  1000  pounds  of  a  high-grade  mixture 
deriving  a  large  part  of  its  nitrogen  from  nitrate  of  soda, 
and  the  remainder  from  quickly  available  forms,  as  blood, 
fish,  cotton-seed  meal  and  tankage.  Because  it  continues 
its  growth  late  in  fall,  tankage,  which  is  less  available 
than  the  other  materials,  is  valuable.  The  minerals  should 
be  present  in  the  soil  in  abundance.  Stable  manure  is 
desirable  because  it  improves  the  mechanical  texture  of 
the  soil,  as  well  as  to  supply  plant-food. 

CONDIMENTAL  OR  SWEET  HERBS 

There  is  a  large  number  of  sweet  herbs  common  to 
European  gardeners  but  of  little  commercial  importance 
in  this  country.  It  is  not  uncommon,  however,  to  find 


Market-Garden  Crops  307 

one  or  more  of  these  plants  in  most  any  American  garden. 
The  fertilization  of  these  crops,  including  dill,  mint,  sage, 
savory,  thyme  and  tansy,  is  in  large  degree  dependent 
upon  the  object  of  their  use,  that  is,  whether  for  leaf 
or  seed.  In  general,  they  require  a  warm  soil  well  sup- 
plied with  all  the  elements  of  plant-food.  A  liberal 
application  of  manure  and  1000  pounds  of  the  basic 
fertilizer  should  be  sufficient. 

In  all  of  the  suggestions  made  as  to  the  fertilization  of 
market-garden  crops,  not  only  has  the  question  of  yield 
been  kept  in  mind,  but  also  the  quality  of  the  product, 
which  is  a  measure  of  salability.  The  question  is  often 
raised  as  to  whether  the  forcing  of  these  crops  by  means 
of  active  fertilizers  may  not  result  in  too  coarse  and  one- 
sided a  growth.  Such  growth  does  frequently  follow  a 
heavy  fertilization  with  nitrogen,  if  accompanied  by  too 
light  a  fertilization  with  minerals.  The  tendency  of  the 
plant  is  to  make  a  normal  development  when  a  sufficiency 
of  all  of  the  fertility  elements  are  present,  but  in  these 
crops  the  object  is  really  a  one-sided  growth  in  many 
cases,  since  that  growth  is  usually  better  adapted  for  the 
purpose  than  that  obtained  under  what  may  be  regarded 
as  normal  conditions.  It  must  be  remembered,  too,  in 
the  growing  of  certain  vegetables,  such  as  radishes,  celery, 
etc.,  or  those  in  which  the  roots  are  the  edible  portion, 
that  commercial  fertilizers  do  not  contribute  any  undesir- 
able flavors.  In  fact,  they  are  often  largely  responsible 
for  those  peculiar  characteristics  which  give  quality; 
whereas,  when  these  vegetables  are  grown  by  the  exclu- 
sive and  necessarily  excessive  applications  —  if  large 
yields  are  to  be  secured  —  of  natural  manures,  undesir- 
able qualities  are  frequently  contributed  by  them. 


CHAPTER  XVI 
ORCHARD  FRUITS  AND  BERRIES 

IT  is  not  until  within  recent  years  that  the  question  of 
manuring  or  fertilizing  fruit  trees  and  berries  has  come  to 
be  of  particular  interest.  This  is  due  primarily  to  the 
fact  that  demands  for  fruit  and  berries  have  been  relatively 
limited  as  compared  with  the  staple  crops.  Hence,  fruit- 
growing as  a  business,  or  on  a  commercial  scale,  is  compara- 
tively new,  though  the  opinion  is  quite  prevalent  among 
fruit-growers  that  trees,  particularly,  are  indigenous  to 
most  soils,  and  grow  freely  like  weeds,  and  that  therefore 
orchard  crops  are  not  as  exhaustive  of  the  fertility  elements 
as  others.  They  cite,  as  an  argument  on  this  point,  the 
fact  that  lands  from  which  timber  has  been  recently 
removed  are  much  more  productive  than  those  upon  which 
many  regular  farm  crops  have  been  grown.  Scientific 
investigation  and  practical  experience,  however,  teach  that 
forest  growth  and  fruit  growth  are  quite  different  in  respect 
to  the  needs  of  fertilizing  elements,  and  that  progressive 
fruit-culture  demands  that  quite  as  much  attention  shall 
be  given  to  the  matter  of  providing  proper  plant-food  as  is 
now  known  to  be  desirable  for  the  other  and  more  common 
crops  of  the  farm  grown  for  profit. 

FRUIT   CROPS  DIFFER  FROM  GENERAL  FARM  CROPS 

It  is  obvious  that  suggestions  as  to  the  character  of  the 
fertilizing  of  the  cereal  crops,  grasses  and  vegetables, 
must  be  somewhat  different  from  these  fruits,  because  the 

308 


Orchard  Fruits  and  Berries  309 

former  differ  from  the  latter  not  only  in  their  habits  of 
growth,  but  in  the  character  and  composition  of  the  crop 
produced,  and  in  their  relation  to  soil  exhaustion.  General 
farm  crops,  with  few  exceptions,  require  but  one  year  for 
the  entire  processes  of  vegetation  and  maturation.  Fruit 
crops,  as  a  rule,  require  a  preparatory  period  of  growth  of 
tree  or  bush  before  any  crop  is  produced,  which  is  longer 
or  shorter  according  to  the  kind  of  fruit.  Furthermore, 
after  the  fruit-bearing  period  begins,  the  vegetative  proc- 
esses do  not  cease,  but  are  coincident  with  the  growth  and 
ripening  of  the  fruit.  The  crop  product,  or  the  fruit,  also 
differs  materially  in  its  character  from  the  general  farm 
crop,  or  from  vegetables,  which  reach  their  harvesting 
stage  and  die  in  one  season,  because  for  many  kinds  a  whole 
season  is  required  for  growth  and  development. 

That  is,  in  fruit-growing  it  is  necessary  that  there  shall 
be  a  constant  transfer  of  the  nutritive  juices  from  the  tree 
to  the  fruit  throughout  the  entire  growing  season,  while 
the  growth  for  each  succeeding  year  of  both  tree  and  fruit 
is  dependent  upon  the  nutrition  stored  up  in  buds  and 
branches,  as  well  as  upon  that  which  may  be  derived 
directly  from  the  soil. 

"  In  the  next  place,  the  relation  of  fruit-growing  to  soil 
exhaustion  is  very  different  from  that  in  general-crop 
farming,  because  in  orchards  there  is  an  annual  demand 
for  specific  kinds  and  definite  proportions  of  soil  constitu- 
ents. It  is  really  a  continuous  cropping  of  the  same  kind, 
and  there  is  no  opportunity,  as  in  the  case  of  ordinary  farm 
crops,  to  correct  the  tendency  to  exhaustion  by  a  frequent 
change  of  crops,  or  the  frequent  growth  of  those  which 
require  different  kinds  and  amounts  of  plant-food  con- 
stituents." l 

1  Voorhees,  "Manuring  Orchards."  Lecture  before  Massa- 
chusetts Horticultural  Society,  1896. 


310  Fertilizers 


THE  SPECIFIC  FUNCTIONS    OF   THE    ESSENTIAL  FERTILIZING 
CONSTITUENTS 

It  must  be  admitted,  however,  that  the  general  principles 
of  manuring,  as  applied  to  farm  crops,  also  apply  to  fruit 
and  berry  crops ;  that  is,  the  essential  manurial  constitu- 
ents must  be  the  same. 

"A  fruit  tree  will  not  make  normal  growth  in  a  soil 
destitute  of  nitrogen.  That  nitrogen  encourages  leaf 
growth  is  a  recognized  fact,  and  since  trees  grow  by  means 
of  both  leaf  and  root,  its  presence  is  required  in  the  soil  in 
order  to  promote  the  growth  and  extend  the  life  of  the 
tree.  It  is  very  evident,  too,  that  potash  is  an  essential 
constituent  in  the  growth  of  fruits,  not  only  because  it 
constitutes  a  large  proportion  of  the  ash  of  the  wood  of 
the  apple,  pear,  cheery  and  plum,  and  more  than  50  per 
cent  of  the  ash  of  fruit,  but  because  it  forms  the  base  of 
the  well-known  fruit  acids.  Phosphoric  acid  is  also  very 
essential  in  order  to  nourish  a  tree  properly,  as  well  as  to 
insure  proper  ripening,  though  it  is  apparent  from  such 
investigations  as  have  been  made  that  this  constituent  is 
relatively  of  less  importance  than  for  the  cereals." 

It  is  also  a  matter  of  common  observation  that  in  the 
production  of  stone-fruits,  particularly,  lime  is  an  impor- 
tant constituent.  Its  functions  seem  to  be  to  strengthen 
the  stems  and  woody  portion  of  the  tree,  to  shorten  the 
period  of  growth,  and  to  hasten  the  time  of  ripening. 
Fruit  trees  growing  on  soils  rich  in  lime  show  a  stocky, 
steady,  vigorous  growth,  and  the  fruit  ripens  well,  while 
those  on  soils  which  contain  but  little  lime,  particularly 
the  clays,  appear  to  have  an  extended  period  of  growth, 
the  result  of  which  is  that  the  wood  does  not  mature  and 
the  fruit  does  not  ripen  properly. 


Orchard  Fruits  and  Berries  311 


THE    CHARACTER   OF    SOIL  AN    IMPORTANT   CONSIDERATION 

Soils  which  possess  good  mechanical  condition,  are  rich 
in  the  essential  constituents,  —  nitrogen,  phosphoric  acid 
and  potash,  —  contain  a  good  proportion  of  lime  and  are 
well  drained  and  cultivated,  are  naturally  well  adapted  for 
fruit  trees,  as  well  as  for  other  crops,  and  the  exhaustion  of 
such  soils  will  not  become  apparent  for  a  long  time.  But 
soils  of  this  character  are  the  exception  rather  than  the 
rule,  and  the  growth  of  fruit  on  those  which  possess  the 
opposite  characteristics  cannot  be  continued  for  any  con- 
siderable period  without  an  artificial  supply  of  the  fertility 
elements.  In  fact,  it  is  doubtful  whether  it  ever  pays  to 
attempt  to  grow  fruits  on  soils  of  the  latter  character  with- 
out supplying  them  with  an  abundance  of  the  essential 
fertilizer  elements. 

In  the  matter  of  berries,  which  are  crops  especially  well 
adapted  to  soils  which  possess  a  light,  open  character,  but 
which  are  not  naturally  supplied  with  the  essential  plant- 
food  constituents,  proper  manuring  becomes  of  even  more 
importance  than  for  the  tree  fruits;  though,  because  of 
their  shorter  period  of  life,  one  or  two  good  crops  may  be 
secured  without  heavy  fertilization. 

On  the  whole,  however,  for  all  of  these  crops  the  great 
need  at  the  present  time  is  for  a  larger  use  of  fertilizing 
materials,  not  only  because  a  larger  yield  may  be  obtained 
thereby,  but  because  the  quality  of  the  product  is  far  supe- 
rior to  that  grown  under  conditions  which  are  not  perfect  in 
this  respect.  Quality,  which  is  determined  by  size  and 
appearance,  is,  other  things  being  equal,  largely  dependent 
upon  an  abundant  supply  of  plant-food.  It  is  manifestly 
impossible  to  include  all  fruit  and  berry  crops  in  one  general 
group,  though  possessing  points  of  resemblance,  because 


312  Fertilizers 

the  different  ones  vary  more  or  less  in  their  character. 
The  trees  of  certain  of  them  are  long-lived,  —  40  years  or 
more,  —  while  others  are  comparatively  short-lived  — 
10  years  or  less.  In  certain  of  them  the  cropping  period 
is  short ;  the  fruit  ripens  at  once,  while  in  others  the  ripen- 
ing period  extends  over  a  considerable  time.  They  also 
differ  in  reference  to  their  demands  for  plant-food,  certain 
of  them  requiring  an  abundance  of  available  food,  while 
others  can  readily  absorb  the  food  necessary  for  their 
growth  from  relatively  insoluble  compounds.  In  the 
discussion,  similar  recommendations  may  be  made  in 
many  cases,  though  it  is  desirable  that  each  class  of  fruits 
shall  be  considered  separately,  and  also  that  distinctions 
should  be  made  between  what  are  regarded  as  good  soils, 
as  medium  soils  and  as  poor  soils,  in  respect  to  their  content 
of  plant-food. 

THE   GENERAL  CHARACTER  OF  THE   FERTILIZING 

It  must  be  borne  in  mind,  also,  that  inasmuch  as  the  fruit 
crop  is  not  derived  from  annual  plants,  but  from  perennials, 
the  character  of  the  feeding  may  be  very  different  from 
that  in  which  the  entire  plant  serves  as  a  crop,  as  is  the 
case  with  the  cereals  and  most  vegetables.  Hence,  the 
fertilizers  applied  need  not  all  be  of  such  a  character  as  to 
be  immediately  available.  That  is,  the  fertilizing  mate- 
rials may  be  such  as  to  provide  for  a  gradual  and  continuous 
feeding.  Those  forms  which  decay  relatively  slowly  are, 
perhaps,  quite  as  good,  if  not  better,  for  many  kinds  of 
fruits  than  those  which  by  virtue  of  their  solubility  and 
immediate  availability  are  more  stimulative  in  their  char- 
acter. Those  fertilizers  which  do  not  contribute  to  the 
immediate  feeding  of  the  tree  or  plant,  but  rather  add  to 


Orchard  Fruits  and  Berries  313 

the  reserves  of  potential  plant-food  in  the  soil,  should, 
however,  in  many  cases  be  supplemented  by  those  which 
act  more  quickly,  in  order  to  supply  an  abundance  of  avail- 
able food  at  special  times  and  seasons.  In  general,  there- 
fore, a  basic  formula,  the  chief  claim  of  which  is  that  it 
furnishes  large  percentages  rather  than  specific  propor- 
tions or  forms  of  plant-food,  may  be  more  reasonably 
adopted  for  fruits  and  berries  than  for  other  crops,  be- 
cause it  may  be  applied  with  advantage  to  all  of  the 
fruits,  the  amounts  to  be  applied  to  be  adjusted  to  meet 
the  requirements  of  the  different  kinds  of  crop  and  the 
different  kinds  of  soil.  Fertilizers  which  have  been 
found  to  be  very  serviceable  for  fruit  crops  have  been 
made  according  to  the  following  formulas^  the  materials 
of  which  are  familiar  to  all,  and  may  be  readily  obtained 
from  dealers:  (1)  One  part,  or  100  pounds  each,  of 
ground  bone,  acid  phosphate  and  muriate  of  potash;  or 
(2)  a  mixture  of  one  and  one-half  parts,  or  150  pounds, 
of  ground  bone,  and  one  part,  or  100  pounds,  of  muri- 
ate of  potash ;  the  mixture  of  either  to  be  applied  in  all 
cases.  For  fruit  trees  on  soils  of  good  natural  charac- 
ter, further  additions  of  more  active  forms  of  the  va- 
rious constituents  may  not  be  needed,  while  on  light 
soils,  or  those  of  a  medium  character,  or  for  berries, 
they  should  be  added. 

The  chief  point  to  observe  is  that  an  excess  of  nitrogen 
must  be  avoided,  and  that  if  this  element  is  applied  in 
active  forms,  it  should  be  used  at  such  times  as  to  enable 
the  plant  to  appropriate  it  early  in  the  season,  and  thus 
become  assimilated  before  the  beginning  of  winter,  the 
danger  from  too  great  an  excess  of  nitrogenous  fertilizers 
being  that  it  causes  a  too  rapid  growth  of  both  wood  and 
fruit,  which  do  not  ripen  well. 


314  Fertilizers 


THE  APPLICATION  OF  FERTILIZERS  FOR  FRUITS 

A  point  which  should  be  carefully  observed  in  the  fer- 
tilizing of  orchards  is  the  method  of  application.  The 
fertilizers  should,  as  far  as  possible,  be  distributed  through- 
out the  lower  layers  of  soil,  where  the  feeding  roots  are 
located.  If  applied  wholly  on  the  surface  of  the  soil,  the 
tendency  of  the  root  is  to  go  to  that  point,  or  where  the 
food  is,  and  trees  which  have  the  larger  proportion  of  the 
feeding  roots  near  the  surface  are  more  liable  to  suffer 
from  drought  than  those  which  have  them  distributed  at 
greater  depths  in  the  soil.  Hence,  in  the  application  of 
fertilizers  to  orchards,  particularly  in  the  early  life  of  the 
trees,  they  should,  as  far  as  possible,  be  well  worked  into 
the  soil,  which  may  be  readily  accomplished  by  applying 
upon  the  surface  before  plowing.  The  after-fertilizing,  if 
it  seems  desirable  to  leave  the  orchard  in  sod,  may  be 
upon  the  surface,  though  in  that  case  the  soluble  fertilizers 
are  preferable,  since  they  would  rapidly  descend,  while  the 
insoluble  would  do  so  more  slowly,  or  only  as  rapidly  as 
they  became  soluble. 

THE  FERTILIZING  OF  APPLES  AND  PEARS 

The  necessity  for  the  application  of  fertilizers  in  the 
growing  of  apples  and  pears  is  largely  due  to  the  fact  that 
it  is  really  a  continuous  cropping  of  the  same  kind,  and 
therefore  more  exhaustive  than  a  cropping  which  removes 
more  plant-food  in  the  same  period  of  time.  While  upon 
good  soils  the  trees  may  be  able  to  acquire  sufficient  food 
to  mature  maximum  crops  for  a  considerable  period,  the 
life  of  the  tree,  as  well  as  the  character  of  the  fruitage,  will 
be  very  favorably  influenced  by  the  fertilization. 


Orchard  Fruits  and  Berries  315 

An  experiment 1  bearing  upon  this  point  is  very  instruc- 
tive, as  indicating  the  need  of  manures  for  fruit  trees,  not 
only  in  reference  to  the  amount  removed,  but  also  in  refer- 
ence to  the  proportions  of  the  essential  constituents  re- 
quired. This  study  shows  that  the  plant-food  contained 
in  20  crops  of  apples,  of  15  bushels  to  the  tree,  and  35 
trees  to  the  acre,  and  in  the  leaves  for  the  same  period, 
amounts,  in  round  numbers,  to  1337  pounds  of  nitrogen, 
310  of  phosphoric  acid  and  1895  of  potash.  These 
amounts  of  plant-food  are  compared  with  the  amounts  that 
would  be  removed  by  20  years'  continuous  cropping  with 
wheat,  assuming  an  average  yield  of  15  bushels  of  wheat 
to  the  acre,  and  7  pounds  of  straw  to  3  bushels  of  grain ; 
viz.,  660  pounds  of  nitrogen,  211  of  phosphoric  acid  and 
324  of  potash.  By  this  comparison  it  is  shown  that  the 
20  crops  of  apples  remove  more  than  twice  as  much  nitro- 
gen, half  as  much  again  of  phosphoric  acid  and  nearly 
three  times  as  much  potash  as  the  20  crops  of  wheat. 

These  results  are  valuable  in  indicating  the  rate  of  soil 
exhaustion  by  apple-growing.  It  is  to  be  remembered, 
however,  that  the  larger  root  development  of  the  tree 
would  enable  it  to  draw  its  nourishment  from  a  larger 
area  of  soil  than  is  the  case  with  wheat,  and  thus  probably 
permit  of  normal  growth  for  a  longer  period. 

Too  many  are  satisfied  with  short  crops  of  medium  fruit, 
with  off-years  and  with  short-lived  trees,  largely  because 
they  do  not  know  that  all  of  these  conditions  may  be  im- 
proved by  a  proper  feeding  of  the  tree,  and  that  such  feed- 
ing will  usually  result  in  a  very  largely  increased  profit. 

Statistics  gathered  in  the  state  of  New  Jersey  2  show  that 

1  Cornell  Exp.  Sta.,  Bulletin  No.  103,  "Soil  Depletion  in 
Respect  to  the  Care  of  Fruit  Trees." 

2  Bulletin  No.  119,  New  Jersey  Experiment  Station. 


316  Fertilizers 

over  90  per  cent  of  the  commercial  apple-growers  in  the 
southern  and  central  sections  use  fertilizers  or  manures  for 
their  orchards,  whereas,  in  the  northern  section  about 
70  per  cent  use  manures.  In  the  northern  section  the 
orchards  are  usually  located  upon  soils  of  a  very  high 
natural  strength,  and  which  are  peculiarly  well  adapted 
for  the  growing  of  fruits,  while  in  the  central  and  southern 
sections,  the  soils  in  many  sections  are  of  medium,  if  not 
of  very  low,  fertility.  Hence,  while  the  larger  proportion 
of  the  growers  use  fertilizers  or  manures  upon  the  poor 
soils,  a  very  considerable  number  use  manures  for  orchards 
located  upon  soils  which  are  regarded  as  of  the  best ;  yet 
all  claim  that  it  is  a  paying  practice. 

There  is  also  a  difference  in  the  time  at  which  manuring 
or  fertilizing  should  begin.  When  the  soil  is  naturally 
good  the  fertilization  need  not  begin  with  the  setting  of  the 
tree,  as  the  food  obtainable  is  usually  sufficient  to  provide 
for  a  good  growth  of  leaf  and  wood,  and  in  many  cases 
maximum  crops  of  fruit  for  a  number  of  years,  though 
even  here  fertilization  should  preferably  begin  as  soon  as 
large  crops  are  produced,  whereas,  on  the  lighter  soils, 
fertilization  should  begin  when  the  tree  is  set. 

The  amounts  to  be  applied. 

For  these  crops,  either  of  the  basic  mixtures  suggested 
(p.  313)  will  provide  a  sufficient  proportion  of  nitrogen, 
except  possibly  upon  the  more  sandy  soil.  On  light  soils, 
the  necessity  for  liberal  fertilization  with  nitrogen  is  fre- 
quently apparent.  In  many  cases  it  is  possible  to  obtain 
the  necessary  nitrogen  from  the  growing  of  leguminous 
crops,  as  crimson  clover,  though  when  these  are  used  they 
should  be  plowed  down  early  in  the  spring,  in  order  that 
their  growth  may  not  interfere  with  the  growth  of  the  tree. 


Orchard  Fruits  and  Berries  317 

If  they  are  allowed  to  remain  until  mature,  they  absorb 
not  only  the  food  that  may  be  necessary  for  the  growth  of 
tree  and  fruit,  but  the  moisture  also,  and  thus  they  fre- 
quently injure  rather  than  improve  the  crop  prospects. 

On  soils  of  good  natural  character,  the  fertilization  of 
apples  and  pears  should  begin  as  soon  as  the  trees  reach 
the  bearing  period,  and  an  annual  application  of  400  pounds 
to  the  acre  of  either  formula  should  be  made,  preferably  in 
early  spring,  and  plowed  in.  As  they  grow  older  and  the 
yield  of  fruit  is  larger,  the  amounts  should  be  increased. 
While  no  definite  rules  can  be  laid  down  as  to  the  most 
profitable  amounts  to  apply,  the  best  growers  find  that  it 
pays  to  use  from  1000  to  1500  pounds  annually  of  mixtures 
which  furnish  practically  the  amounts  and  kinds  of  plant- 
food  contained  in  the  formulas  suggested.  The  profit  is 
found,  not  only  in  the  larger  yield,  but  in  the  quality  of  the 
fruit  and  in  the  increased  tendency  toward  continuous 
crops,  and  in  longer  life  of  the  tree.  On  soils  of  medium 
character  the  fertilization  should  begin  earlier,  and  the 
amounts  of  the  basic  fertilizer  should  be  larger.  In  many 
cases,  too,  nitrogen,  in  addition  to  that  contained  in  the 
basic  formula,  should  be  added,  the  kind  and  form  de- 
pending, perhaps,  upon  the  relative  cost  more  than  upon 
any  other  one  thing,  the  minimum  amount  to  be  20  pounds 
to  the  acre,  or  an  equivalent  of  125  pounds  of  nitrate  of 
soda. 

On  poor  soils,  the  necessity  for  fertilizing  is  naturally 
greater  than  for  either  of  the  others.  In  fact,  on  these 
liberal  fertilization  —  500  pounds  to  the  acre  of  basic 
formula  No.  2  —  should  precede  the  setting  of  the  trees, 
and  be  continued  annually.  On  these  soils,  too,  green 
manuring  as  a  source  of  nitrogen  can  be  practiced  with 
safety  for  a  longer  period  than  in  the  preceding  case.  In 


318  Fertilizers 

the  presence  of  an  abundance  of  minerals,  the  need  for 
nitrogen  is  indicated  by  the  color  of  the  foliage.  If  it 
lacks  vigor  and  is  yellow  in  the  spring,  rather  than  green, 
a  dressing  of  from  100  to  150  pounds  of  nitrate  of  soda  will 
supply  the  needs  to  better  advantage  than  any  other  form. 


PEACHES 

Peaches  differ  from  apples  and  pears  in  respect  to  fertiliz- 
ing because  the  period  of  development  of  the  tree,  prepara- 
tory to  bearing,  is  shorter,  and  because  the  cropping  is 
usually  much  more  exhaustive.  Hence,  the  demands  for 
added  plant-food  are  proportionately  greater  in  the  early 
life  of  the  tree,  and  are  different,  because  of  their  more 
rapid  growth.  That  is,  forms  of  nitrogen  that  are  more 
available  are  preferred  to  the  slowly  available  materials 
recommended  for  apples  and  pears. 

The  need  of  fertilizers. 

The  results  of  an  experiment  conducted  by  the  New 
Jersey  Experiment  Station  are  interesting  and  valuable, 
as  bearing  upon  this  point.  They  show  the  value  of  fer- 
tilization, not  only  in  increasing  the  yield  of  crops,  but  in 
extending  the  period  of  life  of  the  trees,  and  in  overcoming 
unfavorable  crop  conditions.  The  soil  upon  which  the 
experiment  was  conducted  possessed  only  medium  fertility, 
good  mechanical  condition,  and  was  fairly  representative 
of  soils  naturally  well  adapted  for  peach-growing.  The 
fertilized  plots  received  annually  — 

Nitrate  of  soda 150  Ib. 

Bone-black  superphosphate 350  Ib. 

Muriate  of  potash 150  Ib. 


PLATE  XV.  —  Fertilizers  for  Peaches. 


FIGS.  30  and  31.  —  VIEWS  OF  THE  VINELAND  EXPERIMENTAL  PEACH 
ORCHARD,  NEW  JERSEY  EXPERIMENT  STATION,  SHOWING  (FiG.  30) 
EFFECT  OF  NITROGEN  IN  ADDITION  TO  MINERALS;  FIG.  31,  BELOW, 
MINERALS  ONLY,  No  NITROGEN. 


Orchard  Fruits  and  Berries 


319 


to  the  acre,  whereas  the  manured  plot  received  manure 
at  the  rate  of  20  tons  to  the  acre. 

The   following   tabular   statement   shows   the    results 
obtained : 

I.   THE  YIELD  WITHOUT  MANURE 

Baskets 
to  the  acre 

1884-1891,  inclusive,    8  years,  average  per  year     .     .  .  65.7 

1884r-1895,  inclusive,  10  years,  average  per  year     .     .  .  60.3 

1887-1891,  inclusive,    5  crop  years,  average  per  year  .  105.0 

1887-1893,  inclusive,    7  crop  years,  average  per  year  .  86.2 


II.   THE  YIELD  WITH  COMPLETE  CHEMICAL  MANURE 


1884—1891,  inclusive,    8  years,  average  per  year     . 
1884-1893,  inclusive,  10  years,  average  per  year     . 
1887-1891,  inclusive,    5  crop  years,  average  per  year 
1887-1893,  inclusive,    7  crop  years,  average  per  year 


Baskets 
to  the  acre 

.     164.2 

.     183.4 

.     262.8 

262.0 


III.   THE  YIELD  WITH  BARNYARD  MANURE 

1884r-1891,  inclusive,    8  years,  average  per  year     .     . 
1884-1893,  inclusive,  10  years,  average  per  year     .     . 
1887-1891,  inclusive,    5  crop  years,  average  per  year 
1887-1893,  inclusive,    7  crop  years,  average  per  year 


Baskets 
to  the  acre 

.     169.5 

.     194.7 

.     271.3 

276.8 


IV.   THE  RELATIVE  YIELD  IN  AN  UNFAVORABLE  SEASON 

Baskets 
to  the  acre 

1889,  unmanured 10.9 

1889,  fertilized 152.5 

1889,  manured 162.5 


"  The  first  point  of  importance  and  value  observed  is  in 
reference  to  the  number  of  crops  that  were  secured.  On 
the  unmanured  land,  the  crops  secured  after  eight  years 
were  so  small  as  to  materially  reduce  the  average  for  the 
whole  period,  while  for  the  manured  land  the  average  for 


320  Fertilizers 

the  whole  period  was  not  only  not  reduced,  but  very  materi- 
ally increased;  that  is,  the  crops  secured  on  these  after 
the  trees  on  the  unmanured  land  had  practically  ceased  to 
bear  were  greater  proportionately  than  those  secured  pre- 
vious to  that  tune.  This  was  true  both  for  the  fertilized 
and  manured  land. 

"In  the  next  place,  it  is  shown  that  the  yield  was  very 
materially  increased  by  the  use  of  manures,  either  in  the 
form  of  artificial  or  natural  supplies,  and  the  differences  in 
yield  derived  from  these  two  forms  are  very  slight,  indicat- 
ing that  very  much  smaller  amounts  of  actual  plant-food 
in  quick-acting  forms  were  quite  as  useful  as  larger  amounts 
of  the  less  available  forms  in  which  the  food  exists  in 
natural  manure  products. 

"For  the  ten  years,  the  fertilized  plot  received  250 
pounds  of  nitrogen,  560  of  phosphoric  acid  and  750  of 
potash,  while  the  yard  manure  plot  received  —  assuming 
the  average  composition  of  yard  manure  —  2000  pounds 
of  nitrogen,  2000  of  phosphoric  acid  and  1600  of  potash ; 
yet  with  eight  times  as  much  nitrogen,  nearly  four  times 
as  much  phosphoric  acid  and  more  than  twice  as  much 
potash,  the  yield  was  but  113  baskets  greater,  or  an 
average  of  11  baskets  to  the  acre. 

"In  the  third  place,  it  is  interesting  to  observe  —  and 
it  is  a  point  of  great  importance  —  the  effect  of  an  abun- 
dance of  food  in  overcoming  unfavorable  weather  or  sea- 
sonal conditions.  The  year  1889  was  extremely  unfavor- 
able, and  the  crop  throughout  the  state  was  small.  In  this 
experiment  the  unmanured  plot  yielded  at  the  rate  of  10.9 
baskets  to  the  acre,  while  the  manured  and  fertilized  plots 
both  showed  a  yield  exceeding  150  baskets  to  the  acre. 
The  manure  strengthened  and  stimulated  the  trees,  and 
enabled  them  to  successfully  resist  such  conditions  as  were 
fatal  to  the  crop  on  the  unmanured  land. 


Orchard  Fruits  and  Berries  321 

"This  point  is  one  that  is  seldom  considered  in  cal- 
culating the  advantages  to  be  derived  from  proper  manur- 
ing, though  it  is  of  extreme  value,  since  the  expenses  of 
cultivation,  trimming  and  interest  on  investment  are 
quite  as  great  in  one  case  as  in  the  other." 

Methods  of  fertilizing. 

The  peach  industry  has  so  extended  in  the  past  few  years 
that  soils  of  natural  high  fertility  possessing  ideal  condi- 
tions for  peach-production  have  long  ago  been  utilized. 
The  peach  crop  is  no  longer  a  luxury  in  the  farmers'  homes, 
but  a  staple  food  commodity  in  all  of  the  markets  of  the 
country.  Many  orchards  are  located  on  the  poorer  soils, 
and  many  more  are  being  planted  annually,  and  this  is 
especially  true  of  peaches  which  may  be  grown  success- 
fully on  the  lighter  types  of  soils.  In  order  that  the  health 
and  vigor  of  the  trees  be  maintained  it  is  necessary  to 
supply  plant-food  in  abundance.  At  the  same  tune  the 
demand  for  natural  manures,  yard  and  stable  manure,  has 
increased,  and  with  the  advent  of  motor-drawn  vehicles, 
the  supply  has  decreased,  leaving  the  use  of  commercial 
fertilizers  the  logical  means  of  supplying  the  necessary 
food  for  the  tree. 

If  commercial  fertilizers  are  to  be  used  efficiently,  some- 
thing must  be  known  of  the  habits  of  the  tree  and  of  the 
kinds  and  amounts  of  plant-food  required.  Good,  warm, 
naturally  well-drained  soils,  even  though  they  contain 
relatively  small  amounts  of  plant-food,  are  better  adapted 
for  peaches  than  for  apples,  because  the  former  are  shorter 
lived,  grow  relatively  more  rapidly  and  have  a  relatively 
greater  power  of  acquiring  food  than  the  longer-lived 
trees.  This  statement  brings  out  the  character  of  the  tree. 
Work  done  at  the  New  Jersey  Experiment  Station,  New 


322  Fertilizers 

Brunswick,  shows  the  kinds  and  amounts  of  plant-food 
that  are  needed  in  order  to  grow  the  tree  and  to  make 
mature  fruit.  "  It  was  shown  in  that  experiment  that  an 
acre  of  peaches  would  require  annually  after  coming  to 
the  period  of  bearing,  and  averaging  2000  baskets  of 
peaches  to  the  acre  in  ten  years  — 

Nitrogen 71  Ib. 

Phosphoric  acid 22  Ib. 

Potash 48  Ib. 

or  an  equivalent  each  year  of  nitrogen  equal  to  460  Ib.  of 
nitrate  of  soda,  phosphoric  acid  equal  to  150  Ib.  of  acid 
phosphate  and  potash  equal  to  100  Ib.  of  muriate  of 
potash." 

At  about  the  same  tune  experiments  conducted  in  Ger- 
many showed  the  average  quantities  of  nitrogen,  phos- 
phoric acid  and  potash,  and  lime  removed  by  apples  to  be — 

Nitrogen 71  Ib. 

Phosphoric  acid 20  Ib. 

Potash 80  Ib. 

Lime 95  Ib. 

and  for  pears  the  quantities  removed  to  the  acre  were: 

Nitrogen 91  Ib. 

Phosphoric  acid 18.5  Ib. 

Potash 71  Ib. 

Lime 120  Ib. 

The  results  confirm  in  a  remarkable  manner  those 
obtained  in  this  country  for  peaches,  more  particularly 
the  large  amounts  of  plant-food  required  annually  in  the 
growth  of  these  crops.  In  the  German  experiments,  the 
greater  amounts  of  potash  are  in  all  probability  due  to  the 
more  liberal  supply  at  the  disposal  of  the  German  farmers. 
The  amount  of  lime  is  likewise  interesting  and  remarkable. 


Orchard  Fruits  and  Berries  323 

With  these  figures  in  mind,  it  is  obvious  that  upon  soils 
of  poor  chemical  character,  but  possessing  good  physical 
condition,  much  larger  amounts  would  be  required  than 
upon  those  soils  which  are  well  supplied  in  this  respect,  but 
whatever  the  soil,  the  tree  will  need  additional  food  for 
proper  growth,  assuming,  of  course,  that  a  part  of  the  food 
necessary  is  derived  from  the  stores  of  the  soil.  Assume 
also  that  in  any  case,  and  more  particularly  in  the  case  of 
sandy  soils,  lime  should  be  liberally  used,  because  it  is  a 
well-known  fact  that  the  lime  does  have  a  very  important 
influence  in  causing  fruiting  and  encouraging  that  vigor 
and  stockiness  of  wood  growth  that  is  so  important. 

The  foregoing  points  very  clearly  to  the  need  of  artificial 
fertilization  of  peaches.  No  definite  rules  can  be  laid  down 
as  to  the  amounts  to  be  applied,  and  no  suggestions  made, 
except  that  the  moment  a  tree  is  hungry,  that  moment  food 
should  be  supplied,  and  the  evidence  of  hunger  is  so  apparent 
in  most  orchards  that  much  more  fertilizer  than  is  now  used 
could  be  applied  with  very  great  profit.  One  should 
remember  also  that  not  only  is  the  fertilizer  necessary  in 
order  to  feed  the  plant,  but  that  an  ample  supply  of  food 
contributes  to  the  power  of  the  tree  to  resist  insects  and 
fungous  attacks,  to  outgrow  slight  injuries,  which  would 
result  in  the  absence  of  proper  nourishment  in  very  materi- 
ally injuring  the  fruit  prospects. 

In  order  that  the  tree  may  be  fed  the  moment  it  is 
hungry,  an  abundance  of  plant-food,  especially  the  minerals, 
should  be  at  its  command.  It  is  necessary  to  be  more 
careful  with  the  use  of  nitrogen.  It  has  already  been 
mentioned  that  it  is  well  to  have  the  soil  in  good  condition 
before  setting.  It  is  not  so  necessary  with  peaches  as 
with  apples  and  pears,  but  it  is  a  good  practice  to  make  an 
application  of  300  to  500  pounds  to  the  acre  of  a  mixture 


324  Fertilizers 

of  equal  parts  of  ground  bone,  acid  phosphate  and  muriate 
of  potash  before  the  trees  are  planted,  especially  upon  poor 
soils.  For  later  years  the  following  recommendations 
are  made,  based  upon  the  results  of  experimental  work 
conducted  by  the  New  Jersey  Experiment  Station : 

For  young  trees  —  two  to  three  years  old,  before  coming 
into  bearing : 

150  Ib.  muriate  of  potash  ] 

300  Ib.  acid  phosphate       f  to  the  acre 

100  Ib.  nitrate  of  soda       J 

For  the  first  and  second  year  of  bearing : 

150  Ib.  nitrate  of  soda] 
400  Ib.  acid  phosphate  f  to  the  acre 
100-200  Ib.  muriate  of  potash  J 

During  mature  bearing : 

200  Ib.  nitrate  of  soda     1 

400  Ib.  acid  phosphate       Y  to  the  acre 

200  Ib.  muriate  of  potash  J 

These  mixtures  are  by  no  means  inviolable.  Conditions 
modify  their  use.  The  character  of  the  growth  and  yield 
of  the  trees  will  be  a  suitable  guide  to  the  application  of 
fertilizers.  If  the  yield  is  poor  one  year,  the  application 
of  the  next  spring  may  be  reduced  30  per  cent,  and  also 
where  leguminous  cover-crops  are  grown  as  green-manures, 
the  amount  of  nitrate  of  soda  in  the  mixture  may  be  re- 
duced 25  per  cent.  The  tree  itself  will  show  in  its  growth 
indications  of  either  proper  nourishment  or  lack  of  it 
which  assist  in  the  management  of  the  orchard.  (See  Figs. 
30  and  31,  Plate  XV.) 

Whatever  the  fertilization,  it  should  be  remembered 
that  the  soil  should  be  abundantly  supplied  with  decaying 


Orchard  Fruits  and  Berries  325 

vegetable  matter  because  this  humus-forming  material 
assists  constantly  by  improving  the  physical  character 
of  the  soil  and  the  stores  of  plant-food,  besides  lending 
great  aid  in  the  conservation  and  better  distribution  of 
water,  the  one  factor  more  than  any  other  which  controls 
size  and  quality  of  crop. 

Many  orchardists  use  much  larger  amounts  of  fertilizer 
than  is  here  recommended,  though  if  the  suggestions  con- 
cerning the  method  of  use  are  carried  out,  the  quantities 
named  will  be  found  sufficient  to  supply  all  the  needs  of 
maximum  crops. 

PLUMS,   CHERRIES  AND  APRICOTS 

The  fertilizing  of  these  fruits,  when  grown  on  the  differ- 
ent classes  of  soils,  need  not  differ  materially  from  that 
recommended  for  peaches  under  the  same  conditions, 
though  cherries,  particularly,  require  in  addition  to  the 
essential  constituents,  nitrogen,  phosphoric  acid  and  pot- 
ash, a  relatively  greater  supply  of  lime,  and  this  substance 
should  be  applied  in  addition  to  the  regular  fertilization. 
Care  should  also  be  exercised  in  the  application  of  nitro- 
gen, in  order  to  prevent  a  too  great  development  of  leaf 
and  branch.  Unless  these  trees  show  a  decided  need  for 
nitrogen,  a  medium  application  of  the  second  basic  formula 
(p.  313)  will  furnish  sufficient  for  their  needs. 

CITROUS  FRUITS 

These  products  —  the  oranges,  lemons  and  the  like  — 
belong  to  a  distinct  class  of  fruits,  and  the  experience 
already  gained  in  their  fertilization  is  such  as  to  make 
applicable  the  suggestions  concerning  peaches,  plums  and 
apricots.  On  the  lighter  sandy  soils  of  Florida,  which  are 


326  Fertilizers 

naturally  well  adapted  for  oranges,  growers  have  found 
potash  to  be  a  specially  important  element  in  manures. 
The  nitrogen  and  phosphoric  acid  should  be  accompanied 
by  a  larger  proportion  of  potash  than  is  recommended 
for  the  stone  fruits.  Great  care  should  be  exercised  in  the 
use  of  nitrogen,  though  in  the  case  of  these  semi-tropical 
crops  the  danger  from  immature  growth,  as  in  the  case  of 
fruits  for  the  more  northern  climates,  is  not  so  marked. 

SMALL-FRUITS 

These  crops  do  not  differ  from  those  already  discussed 
in  reference  to  their  needs  for  liberal  fertilization,  yet  be- 
cause of  their  different  character  of  growth,  the  method  of 
fertilization  should  be  somewhat  different.  They  are,  as 
a  rule,  crops  which  require  a  shorter  preparatory  season,  and 
have  a  shorter  period  of  bearing  life.  The  strawberry, 
for  example,  does  not  advantageously  bear  more  than  two 
crops  without  resetting,  whereas  the  blackberry  and  rasp- 
berry may  range  in  life  from  four  to  eight  years,  and  the 
gooseberry  and  currant  are  relatively  long-lived,  provided 
they  are  supplied  with  an  abundance  of  food.  In  respect 
to  their  general  character,  they  correspond  more  nearly 
with  the  vegetable  crops  than  with  the  cereal  grains,  in 
that  they  possess  a  relatively  higher  market  value  and  a 
lower  fertility  value  than  these,  and  the  period  of  growth 
and  development  of  the  fruit  is  much  shorter.  Therefore, 
natural  sources  of  plant-food  may  be  largely  ignored  in 
their  growth,  and  the  more  quickly  available  —  particu- 
larly nitrogenous  and  phosphatic  —  materials  supplied. 

Strawberries. 

In  the  case  of  the  strawberry,  the  preparatory  period 
of  growth  of  the  plant  before  bearing  is  but  one  year,  and 


Orchard  Fruits  and  Berries  327 

the  crop  that  may  be  obtained  is  largely  dependent  upon 
the  strength  and  vigor  of  plant  which  has  been  acquired 
during  this  period.  Hence,  it  is  desirable  that  the  soil  in 
which  the  plants  are  set  should  be  abundantly  provided 
with  the  mineral  elements,  particularly  with  soluble  and 
available  phosphoric  acid;  hence  an  application  of  from 
500  to  800  pounds  to  the  acre  of  basic  formula  No.  1  (p. 
313)  is  recommended.  The  nitrogen  should  also  be  in 
quickly  available  forms,  and  should  be  supplied  in  suffi- 
cient quantities  at  time  of  setting  the  plant  to  enable  it 
to  mature,  and  thus  to  withstand  the  rigors  of  winter. 
Hence,  an  additional  application  of  100  pounds  of  dried 
blood,  or  its  equivalent  in  nitrate  of  soda,  is  advisable,  par- 
ticularly on  soils  not  previously  well  enriched  with  organic 
nitrogenous  matter.  In  the  spring  of  the  season  during 
which  the  first  crop  is  harvested,  an  application  of  a  quick- 
acting  fertilizer  rich  in  nitrogen  is  desirable,  since  it  not 
only  provides  for  an  early  and  strong  growth  of  plant,  but 
a  better  setting  of  fruit,  if  other  conditions  are  favorable ; 
and  frequently,  with  a  full  setting,  top-dressings  with 
nitrate  of  soda  are  useful,  in  order  to  insure  the  full  develop- 
ment of  the  crop.  Many  growers,  therefore,  who  have 
supplied  the  soil  liberally  with  minerals  and  nitrogen, 
both  at  time  of  setting  the  plants  and  in  the  following 
spring,  make  top-dressings  of  nitrate  of  soda  (about  100 
pounds  to  the  acre),  preferably  after  the  plant  has  blos- 
somed, in  order  to  insure  a  sufficiency  of  this  element. 
This  should  be  applied  at  this  time  rather  than  later 
in  the  season,  since  later  applications  have  a  tendency 
to  cause  a  soft  growth  of  fruit,  and  thus  injure  shipping 
qualities. 

Some  growers  find  it  a  better  practice  to  supply  available 
nitrogen  in  the  mixture  used  at  the  time  of  setting  and  in 


328  Fertilizers 

spring  rather  than  make  partial  applications  of  nitrate  of 
soda ;  and  others  prefer  to  use  nitrate  of  soda  alone  at  the 
time  of  setting  and  supply  the  minerals  as  a  top-dressing 
during  the  summer.  If  a  complete  fertilizer  containing 
available  nitrogen  is  to  be  used  as  above  suggested,  400  to 
600  pounds  of  the  formula  given  on  page  313  would  give 
excellent  results. 

Raspberries  and  blackberries. 

Raspberries  and  blackberries  also  require  a  soil  well 
enriched  with  the  mineral  elements,  which  insure  an  abun- 
dant and  strong  growth  of  canes.  The  need  for  nitrogen, 
while  apparent,  is  less  marked  than  in  the  case  of  the  straw- 
berries, and  the  slower-acting  forms  serve  a  good  purpose, 
provided  they  are  not  applied  in  too  great  quantities,  so  as 
to  encourage  a  late  growth  of  plant,  which  does  not  fully 
mature.  The  main  object  is  to  obtain  strong,  well-ripened 
canes,  and  this  can  be  accomplished  with  the  slowly  avail- 
able nitrogenous  substances,  provided  an  abundance  of  the 
minerals  is  present.  An  annual  application  in  spring  of 
500  pounds  to  the  acre  of  basic  formula  No.  2  (p.  313)  will 
furnish  sufficient  food  on  soils  of  good  character,  though  on 
lighter  soils  additional  nitrogen  should  be  supplied,  pref- 
erably in  forms  not  too  active.  The  practice  of  applying 
quick-acting  nitrogen  early  in  the  spring,  after  plants 
have  blossomed,  has  been  followed  with  great  success, 
particularly  upon  the  lighter  soils,  as  it  encourages  a 
more  complete  development  of  fruit,  though  it  should 
be  used  with  caution,  since  the  fruit  canes  of  both  the 
present  year  and  those  which  provide  the  plant  for  the 
next  year  naturally  grow  in  the  same  bed,  and  the  young 
canes  may  not  mature  properly  if  too  heavy  applications 
of  nitrogen  are  made. 


Orchard  Fruits  and  Berries  329 

Currants  and  gooseberries. 

These  are  crops  which,  under  average  conditions,  are 
seldom  heavily  fertilized,  though  fertilizing  is  usually 
followed  with  great  profit.  They  are  less  likely  to  need 
nitrogen  than  the  other  crops  mentioned,  and  a  too  heavy 
fertilization  with  this  element  has  a  tendency  to  encourage 
the  development  of  mildew,  the  disease  so  common  to  these 
crops.  In  common  with  the  other  crops  mentioned,  they 
should  be  abundantly  supplied  with  the  minerals,  phos- 
phoric acid  and  potash,  and  the  basic  formula  already 
recommended  (p.  313)  may  be  used  in  all  cases  with  profit 
at  the  rate  of  500  to  1000  pounds  to  the  acre.  The  addi- 
tional nitrogen  needed  may  be  provided  by  the  slow-acting 
materials.  Many  growers  find  such  waste  products  as 
wool  and  hair  of  great  advantage  in  the  growing  of  these 
crops. 

Cranberries. 

This  crop  is  very  peculiar  in  its  habits  of  growth,  and 
also  in  its  choice  of  soils.  It  thrives  upon  muck  soils  and 
upon  sand.  Experiments  conducted  by  the  New  Jersey 
Experiment  Station  show  that  the  value  of  fertilization 
of  cranberries  depends  quite  as  much  upon  the  drain- 
age and  irrigation  of  a  bog  as  it  does  upon  the  soil. 
When  these  conditions  are  satisfactory,  liberal  applica- 
tions of  minerals,  particularly  phosphoric  acid,  upon 
muck  soils  increase  the  growth  of  vine  and  the  size  and 
quantity  of  the  berries.  On  such  soils  400  pounds  of  acid 
phosphate  and  100  pounds  of  muriate  of  potash  may  be 
applied. 

Upon  light,  sandy  soils,  nitrogen  is  quite  as  important  as 
phosphoric  acid  and  potash,  but  it  is  necessary  to  exercise 


330  Fertilizers 

great  care  in  the  application  of  nitrogen  because  it  is  likely 
to  cause  too  great  a  growth  of  vine  at  the  expense  of 
fruiting.  In  general  150  pounds  of  nitrate  of  soda,  300 
pounds  of  acid  phosphate  and  100  pounds  of  muriate  of 
potash  to  the  acre  is  sufficient  where  a  uniform  growth 
of  vine  is  present.  At  all  events,  the  fertilization  of  cran- 
berries is  of  very  recent  origin  and  no  definite  rules  can  be 
laid  down.  It  is  an  individual  problem  with  each  grower. 
The  recommendations  above  are  based  upon  work  done 
by  the  New  Jersey  Experiment  Station  by  the  author. 
The  results  obtained  by  the  Massachusetts  Experiment 
Station  under  Cape  Cod  conditions  seem  to  contradict  the 
New  Jersey  results. 

GRAPES 

Grapes  are  more  exhaustive  as  a  crop  than  most  of  the 
fruit  crops,  largely  because  of  the  larger  total  crop  har- 
vested, and  the  special  need  is  for  phosphoric  acid  and 
potash.  These  elements  may  be  supplied  by  the  basic 
formula  (p.  313),  and  very  liberal  dressings  are  recom- 
mended —  from  1000  to  2000  pounds  to  the  acre  annually 
—  after  the  bearing  period  begins.  On  light  soils,  an 
annual  spring  dressing  of  nitrate  of  soda,  at  the  rate  of 
200  pounds  to  the  acre,  is  also  desirable,  in  order  to  encour- 
age rapid  and  large  early  growth  of  leaf  and  vine,  though 
this  dressing  may  be  omitted  if  the  growth  of  clover  as  a 
green-manure  is  practicable.  The  latter,  however,  as  when 
used  in  connection  with  the  other  fruits  mentioned,  should 
not  be  allowed  to  mature,  but  rather  be  plowed  down  early 
in  the  season. 

The  main  point  in  the  fertilizing  of  all  fruits  is  to  pro- 
vide an  abundance  of  the  mineral  elements,  and  to  give 


Orchard  Fruits  and  Berries  331 

particular  attention  to  fertilization  with  nitrogenous 
materials.  It  must  be  remembered  that  it  is  the  fruit, 
not  the  wood,  that  constitutes  the  crop,  and  that  all  the 
energies  should  be  directed  toward  the  development  of 
such  a  tree  or  vine  as  will  best  contribute  toward  this  end. 


CHAPTER  XVII 
FERTILIZERS   FOR   VARIOUS   SPECIAL   CROPS 

IN  addition  to  the  generally  familiar  crops  already 
described,  there  are  certain  special  ones,  not  distinct 
from  the  others  because  they  are  of  less  importance, 
but  rather  because  they  are  only  grown  in  certain  lo- 
calities. 

COTTON 

Among  these  special  crops,  cotton  takes  first  rank, 
because  it  is  one  of  the  leading  crops  of  the  country, 
occupying  wide  areas,  and  exercising  fully  as  great  an 
influence  upon  our  agricultural  prosperity  as  any  other 
of  our  American  staples. 

The  climate  suitable  for  the  growing  of  cotton  is  con- 
fined to  about  one-quarter  of  the  area  of  the  country, 
and  in  this  area  it  occupies  a  more  important  position 
than  any  other  crop  grown  there. 

In  the  earlier  history  of  its  cultivation,  the  methods 
employed  were  not  such  as  to  encourage  the  largest 
yield.  In  the  first  place,  it  was  grown  on  the  poorer 
soils  rather  than  on  the  more  fertile,  and  after  it  had  been 
grown  consecutively  upon  the  same  lands  for  a  number 
of  years,  and  thus  rapidly  exhausting  them,  the  planter, 
instead  of  attempting  to  improve  the  lands,  either  by 
better  methods  of  culture  or  by  the  use  of  manures, 
extended  the  areas  under  cultivation.  After  the  civil 

332 


Fertilizers  for  Various  Special  Crops  333 

war,  when  it  became  still  more  necessary  to  change 
methods,  fertilizers  were  looked  to  as  the  main  reliance, 
rather  than  the  improvement  of  the  character  of  the  soil, 
either  by  judicious  rotation  or  by  manuring.  The  results 
secured  from  the  use  of  fertilizers  at  this  time  were  so 
generally  satisfactory  that  their  large  and  indiscriminate 
use  was  encouraged,  and  this,  without  proper  attempts 
at  the  improvement  of  the  soil  in  other  respects,  hastened 
the  time  when  such  use  did  not  give  profitable  returns. 
The  very  great  importance  of  the  crop  to  the  agriculture 
of  the  leading  cotton  states,  and  the  necessity  of  better 
methods  of  culture,  were  so  fully  appreciated  that  a  scien- 
tific study  of  the  crop  was  then  entered  upon,  and  the 
states  largely  interested  planned,  through  the  aid  of  their 
colleges  and  experiment  stations,  a  wide  series  of  experi- 
ments, which  were  directed  toward  the  solution  of  the 
problems  connected  with  the  feeding  of  the  plant.  The 
results  of  these  experiments  have  been  fruitful  of  such 
valuable  information  as  to  warrant  practical  and  specific 
suggestions  which  have  a  wide  application,  and  which,  if 
followed,  will  result  in  the  improvement  of  the  soil  and  in 
the  economical  increase  in  crop. 

As  already  stated,  the  cotton  crop  is  not  an  exhaustive 
one  in  one  sense,  though  the  methods  of  practice  used  in 
its  growth  have  been  wasteful,  and  thus  have  given  rise 
to  that  belief.  That  is,  a  large  crop  of  cotton  does  not 
remove  from  the  soil  a  very  considerable  amount  of  the 
fertilizer  constituents.  The  following  amounts  are  con- 
tained in  a  crop  yielding  300  pounds  of  lint  to  the  acre : l 

Nitrogen 46  Ib. 

Phosphoric  acid 12  Ib. 

Potash 30  Ib. 

1  Farmers'  Bulletin,  No.  14,  Department  of  Agriculture. 


334  Fertilizers 

Fertilizers  for  cotton. 

In  regard  to  its  need  for  fertilizing,  cotton  may  be 
classed  with  the  cereals  rather  than  with  the  crops  already 
discussed;  and  like  the  cereals,  its  best  growth  is  at- 
tained when  properly  introduced  into  a  rotation  with 
other  crops,  and  the  annual  food  supply  arranged  in  such 
a  manner  as  to  contribute  to  the  larger  yield  of  the  imme- 
diate crop,  as  well  as  to  furnish  an  unused  residue  which 
will  provide  for  an  increase  in  the  yield  of  the  succeeding 
ones.  Of  the  constituents,  phosphoric  acid  seems  to 
exercise  a  greater  influence  upon  the  growth  and  develop- 
ment of  the  cotton  plant  than  any  other  element,  not- 
withstanding the  fact  that  smaller  amounts  are  contained 
in  it  than  of  either  nitrogen  or  potash.  That  is,  it  appears 
that  the  plant  must  have  an  abundance  of  available  phos- 
phoric acid  at  its  command  in  order  that  the  other  con- 
stituents necessary  for  a  full  crop  may  be  freely  absorbed, 
though  on  the  soils  adapted  for  the  crop,  which  naturally 
vary  widely  both  in  their  general  and  special  physical 
characteristics,  but  are  poor  in  the  fertility  elements, 
both  nitrogen  and  potash  must  be  applied,  in  order  that 
maximum  crops  may  be  obtained. 

On  the  whole,  therefore,  though  the  "intensive" 
system  is  not  generally  practiced,  fertilizers  furnishing 
all  of  the  constituents  are  superior  to  those  which  fur- 
nish but  one  or  two ;  yet  when  proper  rotations  are  prac- 
ticed and  leguminous  crops  are  grown  for  the  purpose  of 
improving  the  physical  character  of  the  soil,  as  well  as 
increasing  its  content  of  nitrogen,  the  percentage  of  this 
element  introduced  into  the  fertilizer  may  be  very  largely 
reduced. 

The  conclusions  that  have  been  arrived  at  by  the 


Fertilizers  for  Various  Special  Crops  335 

experiments  conducted  in  the  various  states  have  been 
very  fully  set  forth  in  various  publications,1  and  the 
following  statements  drawn  from  these  indicate  what 
are  believed  to  be  the  advantages  derived  from  the  right 
use  of  fertilizers,  and  the  best  methods  to  be  observed : 
"The  cotton  plant  responds  promptly,  liberally  and 
profitably  to  judicious  fertilization.  The  maturation 
of  the  crop  may  be  hastened,  and  the  period  of  growth 
from  germination  to  fruiting  may  be  so  shortened  as  to 
increase  the  climatic  area  in  which  it  may  be  profitably 
grown.  It  should  be  assigned  to  a  place  in  a  rotation 
system.  One  of  small  grain,  corn  (with  peas)  and  cotton, 
is  well  suited  for  the  conditions  prevailing  in  the  cotton 
belt,  and,  as  with  other  crops,  the  results  derived  from 
the  use  of  fertilizers  for  this  crop  are  much  enhanced  by 
the  proper  preparation  of  the  soil.  It  pays  to  bring 
up  the  cotton  lands  by  mechanical  treatment,  and  es- 
pecially by  introducing  organic  matter.  The  renovating 
crops,  especially  the  cowpea,  are  very  profitably  employed 
as  adjuncts  to  the  fertilization  of  the  crop  itself.  On  the 
majority  of  soils,  too,  it  is  advisable,  and  more  generally 
proves  profitable,  to  use  a  complete  fertilizer,  rather  than 
one  containing  one  or  two  of  the  constituents ;  and  of  the 
forms  of  nitrogen,  organic  (vegetable  and  animal)  is  best 
suited  to  the  cotton,  if  one  form  alone  be  used,  although 
nitrate  of  soda  is  probably  nearly,  if  not  quite,  of  equal 
value.  The  relative  advantages  of  various  proportions 
of  the  different  forms  have,  however,  not  yet  been  fully 
determined;  hence  the  use  of  a  mixture  of  the  best  is  a 

1  Fanners'  Bulletins,  Nos.  14  and  48,  Department  of  Agri- 
culture. Office  of  Experiment  Stations,  Bulletin  No.  33,  De- 
partment of  Agriculture.  Various  bulletins  issued  by  the 
Georgia,  South  Carolina  and  Louisiana  Experiment  Stations. 


336  Fertilizers 

safe  plan,  the  proportions  to  be  determined  by  their  rela- 
tive cost.  In  the  case  of  phosphoric  acid,  superphosphate 
is  to  be  preferred  to  materials  of  an  organic  or  mineral 
nature,  which  are  not  immediately  available.  Of  the 
potash  salts,  no  particular  difference  is  observed  in  the  use 
of  the  different  forms.  The  form  to  be  secured  is  to  be 
based  upon  the  price  of  the  different  forms." 

Formulas  for  cotton  fertilizers. 

While  the  most  judicious  proportions  of  soluble  phos- 
phoric acid,  of  potash  and  of  nitrogen  in  a  complete 
fertilizer  cannot  be  said  to  have  been  determined  with 
entire  accuracy,  the  carefully  conducted  experiments  of 
both  the  Georgia  and  South  Carolina  stations  indicate 
that  for  general  use  1  part  of  nitrogen,  1  of  potash  and 
2f  or  3  of  phosphoric  acid  indicate  the  best  proportions. 
The  amount  of  fertilizer  that  may  be  profitably  used  very 
naturally  varies  widely,  though  medium  rather  than 
very  large  dressings  are  recommended,  not  so  much  be- 
cause the  plant  under  good  soil  conditions  could  not  appro- 
priate and  use  to  advantage  large  amounts,  but  because 
on  the  whole,  soils  used  for  cotton  are  peculiarly  lacking 
in  those  qualities  which  enable  the  proper  distribution 
and  appropriation  of  the  larger  quantity.  For  those  soils, 
then,  the  amounts  per  acre  indicated  by  the  Georgia 
Experiment  Station  are  annually  — 

Nitrogen 20  Ib. 

Available  phosphoric  acid 70  Ib. 

Potash 20  Ib. 

The  South  Carolina  Experiment  Station  recommends 
an  acre  application  of  — 


Fertilizers  for  Various  Special  Crops  337 

Nitrogen 20  Ib. 

Available  phosphoric  acid 50  Ib. 

Potash 15  Ib. 

or,  as  suggested  by  the  Georgia  Experiment  Station, 
perhaps  a  fertilizer  containing  — 

Nitrogen 3% 

Phosphoric  acid  (soluble) 9% 

Potash 3% 

applied  at  the  rate  of  700  pounds  to  the  acre,  would  be 
approximately  the  best  amounts  to  use  under  ordinary 
circumstances. 

Method  of  application. 

The  fertilizer  should  be  applied  in  the  drill  at  the 
time  of  planting,  and  at  the  depth  of  not  more  than 
three  inches,  and  well  mixed  with  the  soil.  In  most  cases 
it  is  best  to  apply  all  of  the  fertilizer  in  one  application 
rather  than  in  fractional  applications,  though  with  lands 
in  superior  condition  profitable  applications  may  be  made 
again  at  the  second  plowing.  Owing  to  the  nearness  of 
the  cotton  belt  to  the  supplies  of  superphosphate,  and  to 
the  cheap  supplies  of  cotton-seed  meal,  the  only  fertilizer 
necessary  to  import  is  potash.  Hence  it  has  become  a 
practice  in  most  sections  for  the  planter  to  make  his  own 
formulas,  using  his  own  supplies  of  phosphoric  acid  and 
nitrogen ;  and  home  mixtures,  made  up  of  acid  phosphate, 
cotton-seed  meal  and  muriate  of  potash,  or  kainit,  are 
largely  used  to  supply  the  demands.  The  following  for- 
mula is  an  example  of  a  good  mixture : 

Acid  phosphate 1200  Ib. 

Cotton-seed  meal 600  Ib. 

Kainit     ....  200  Ib. 


338  Fertilizers 

The  formula  containing  — 

Nitrogen 3% 

Phosphoric  acid 9% 

Potash 3% 

is  also  recommended,  since  an  application  of  700  pounds 
per  acre  will  furnish  the  amounts  and  proportions  of  the 
elements  indicated  as  the  maximum  by  the  Georgia  sta- 
tion. This  formula  is  also  well  suited  for  corn,  if  intro- 
duced into  a  rotation  as  previously  suggested. 

TOBACCO.     (See  Fig.  32,  Plate  XVI.) 

Tobacco  is  another  special  crop  grown  only  in  cer- 
tain localities,  favored  either  by  reason  of  climate  or 
character  of  soil,  or  both.  It  is,  however,  a  very  im- 
portant crop  in  this  country,  and  one  which  requires 
very  careful  attention  in  reference  to  the  amounts  and 
kinds  of  fertilizers  applied,  because  the  fertilization  exer- 
cises an  influence  upon  both  the  yield  and  quality  of  the 
crop.  It  is  an  exhaustive  crop,  drawing  heavily  upon 
both  nitrogen  and  potash.  A  crop  yielding  1000  pounds 
of  leaf  to  the  acre  will  contain,  in  round  numbers,  67 
pounds  of  nitrogen,  9  of  phosphoric  acid  and  85  of  potash  : 
amounts  equivalent  in  nitrogen  to  over  400  pounds  of 
nitrate  of  soda,  of  phosphoric  acid  equivalent  to  75  pounds 
of  acid  phosphate,  and  of  potash  equivalent  to  170  pounds 
of  muriate  of  potash.  It  is  a  fact,  too,  that  tobacco  of  the 
best  quality,  or  that  best  suited  for  cigar  wrappers,  can 
be  grown  to  advantage  only  on  light,  sandy  soils,  —  those 
not  naturally  well  supplied  with  the  fertilizing  constit- 
uents. Thus,  if  large  crops  are  to  be  secured,  the  soil 
must  receive  liberal  supplies  of  food  from  artificial  sources. 


Fertilizers  for  Various  Special  Crops  339 


The  influence  of  fertilizers  on  the  quality  of  the  crop. 

A  point  of  great  importance  in  the  fertilizing  of  tobacco 
is  the  influence  of  the  constituents  applied  on  the  market- 
able quality  of  the  crop,  as  for  certain  purposes,  espe- 
cially for  the  manufacture  of  cigars  and  cigarettes,  the 
tobacco  must  possess  peculiar  characteristics  in  order 
to  bring  the  highest  price  in  the  market.  In  other  words, 
in  the  growing  of  this  crop,  as  is  the  case  in  many  others, 
both  the  yield  and  quality  must  be  taken  into  considera- 
tion, and  frequently  the  latter  point  is  of  quite  as  much 
importance  as  the  former,  though  a  reasonable  yield  must 
be  secured  before  the  influence  of  quality  is  of  practical 
significance.  The  quality  of  the  leaf  is  believed  to  be 
influenced  chiefly  by  the  constituent  potash,  though 
many  growers  object  to  the  use  of  various  nitrogenous 
and  phosphatic  materials,  believing  that  they,  too,  exer- 
cise a  decidedly  unfavorable  influence  upon  the  quality 
of  the  leaf.  Careful  experiments,  however,  do  not  justify 
many  of  the  opinions  of  growers  and  dealers  regarding  the 
effect  of  the  different  materials  upon  the  quality  of  wrapper 
tobacco. 

The  main  points,  therefore,  in  the  fertilizing  of  tobacco 
are  to  see  to  it  that  a  sufficient  quantity  of  plant-food  is 
applied  in  order  to  secure  the  largest  possible  yield  con- 
sistent with  quality,  and  second,  to  avoid  the  use  of  such 
constituents  as  are  positively  injurious. 

The  conclusions  from  Connecticut  experiments. 

Experiments  in  the  application  of  fertilizers  to  to- 
bacco have  been  carried  out  at  the  Connecticut  Experi- 
ment Station  with  great  care  and  skill  for  a  number 


340  Fertilizers 

of  consecutive  years.1  They  lead  to  the  conclusion 
that  "there  is  no  'best'  tobacco  fertilizer,  or  'best' 
formula  for  all  seasons,  even  on  the  same  soil.  A  for- 
mula or  a  form  of  plant-food  which  in  one  season  gives 
the  leaf  a  somewhat  better  quality  than  any  other  may, 
perhaps  the  next  year  and  on  the  same  soil,  prove  inferior 
to  others,  for  reasons  which  can  only  be  surmised. 

"Nevertheless,  by  comparing  the  effects  of  these 
fertilizers  for  a  term  of  years,  it  appears  that  certain 
ones  are,  on  the  whole  and  generally  speaking,  more 
likely  to  impart  a  perfectly  satisfactory  quality  to  the 
leaf  than  certain  others. 

"It  is  doubtless  true  of  tobacco,  as  of  other  crops, 
that  the  liberal  but  not  greatly  excessive  supply  of  readily 
available  plant-food  yearly  required  to  insure  a  paying 
crop  may  be  given  in  a  variety  of  forms  with  equally 
good  results,  on  the  average  of  one  season  with  another, 
and  that,  indeed,  occasional  changes  in  the  form  of  nitro- 
gen and  potash  supplied  may  be  a  distinct  advantage, 
avoiding  always  any  considerable  quantity  of  those 
things,  as  chlorin,  and  sulfuric  or  other  free  acids,  which 
experience  has  shown  may  damage  the  leaf." 

These  conclusions  in  regard  to  the  kind  and  quantity 
of  fertilizing  constituents  required  for  the  growing  of 
tobacco  of  good  quality  confirm  those  arrived  at  by 
experiments  elsewhere,  and  the  suggestions  made  are 
sufficiently  definite  to  guide  in  the  use  of  fertilizers 
for  this  crop.  In  brief,  therefore,  the  tobacco  crop 
must  be  provided  with  an  abundance  of  all  of  the  fer- 
tilizer elements  derived  from  readily  available  forms, 
and  free  from  those  constituents  known  to  exercise  an 

1  Connecticut  Agr.  Exp.  Sta.  Annual  Report,  1897,  Part  IV, 
page  255. 


Fertilizers  for  Various  Special  Crops  341 

unfavorable  influence  upon  the  quality  of  the  product, 
in  order  that  satisfactory  yields  of  good  quality  may  be 
secured. 

Form  of  the  constituents. 

It  has  not  been  shown  that  one  form  of  nitrogen  is 
superior  to  another  under  all  circumstances,  or  in  other 
words,  that  one  form  of  nitrogen  —  as,  for  example, 
ammonia,  or  nitrate,  or  any  particular  form  of  organic 
nitrogen,  vegetable  or  animal  —  is  superior  to  all  others, 
but  rather  that  any  or  all  of  the  good  forms  may  be  used 
in  a  mixture,  provided  a  sufficient  abundance  is  present 
to  insure  a  maximum  yield,  though  not  so  large  an  amount 
in  excess  of  the  minerals  as  to  encourage  a  rank,  coarse 
growth.  Phosphates  have  been  neglected  because  the 
crop  takes  out  very  little,  but  recent  tests  indicate  that 
moderate  use  of  them  gives  a  healthier  crop,  a  somewhat 
larger  crop  and  perhaps  of  somewhat  better  quality. 
The  phosphoric  acid  should  be  in  available  forms,  and  if 
in  these  forms,  must  naturally  be  drawn  largely  from 
superphosphates.  The  potash  should  in  all  cases  be  drawn 
from  sources  free  from  chlorids.  A  fertilizer,  therefore, 
which  contains  the  nitrogen,  either  in  good  organic  forms, 
as  cotton-seed  meal  or  blood,  or  a  mixture  of  these  organic 
forms  with  ammonia  or  nitrate  in  not  too  large  amounts, 
which  contains  the  phosphoric  acid  in  a  soluble  form,  and 
potash  derived  from  products  free  from  chlorids,  —  as 
from  high-grade  sulfate,  or  from  a  carbonate,  or  from 
cotton-hull  ashes,  if  these  are  obtainable,  —  may  be  re- 
garded as  well  adapted  for  the  crop. 

Amounts  to  qpply. 

An  annual  dressing  which  will  furnish  100  pounds  of 
nitrogen,  75  of  phosphoric  acid  and  150  of  potash  to  the 


342  Fertilizers 

acre  may  be  regarded  as  a  minimum  for  soils  of  medium 
quality.  On  lighter  soils  heavier  applications  should 
be  made,  and  on  soils  previously  well  enriched  with  the 
fertilizer  constituents,  the  dressing  may  be  somewhat 
less.  It  must  be  remembered,  however,  that  it  is  not 
economical,  from  the  standpoint  of  either  yield  or  qual- 
ity, to  be  too  sparing  in  the  application  of  fertilizers, 
because  the  plant  requires  large  amounts  of  both  nitro- 
gen and  potash,  and  because  it  is  essential  that  the  plant 
should  have  a  reasonable  excess  of  these  at  its  command, 
in  order  to  overcome  as  far  as  possible  any  unfavorable 
seasonal  conditions  that  may  occur. 

In  the  Connecticut  experiments  already  referred  to, 
amounts  greatly  in  excess  of  those  suggested  have  been 
used  with  advantage,  and  the  following  formulas  are  cited 
as  fair  examples  of  what  would  be  good  fertilizers  for  an 
acre: 

Cotton-seed  meal 2000  Ib. 

Sulfate  of  potash 300  Ib. 

Precipitated  or  dissolved  bone     .     .     .  200  Ib. 

Lime 300  Ib. 

Total    .     .  2800  Ib. 
or 

Cotton-seed  meal 1500  Ib. 

Fish 500  Ib. 

Double  sulfate  of  potash 500  Ib. 

Acid  phosphate 400  Ib. 

Lome       300  Ib. 

Total    .     .  3200  Ib. 

In  Kentucky  and  Virginia,  on  soils  naturally  richer, 
smaller  amounts  have  given  quite  as  good  results.  It  is 
likely,  however,  that  upon  the  very  light  soils  of  certain 
of  the  states  in  which  tobacco  of  high  quality  is  grown, 
notably  Florida,  considerably  increased  amounts  may  be 
used  with  profit. 


Fertilizers  for  Various  Special  Crops  343 

As  sources  of  at  least  part  of  the  nitrogen  and  potash 
in  the  southern  states  particularly,  cotton-seed  meal  and 
cotton-hull  ashes  are  recommended,  because  readily 
obtainable.  These  forms  have  been  found  to  be  good, 
and  they  may  be  obtained  as  cheaply  as  other  forms  as 
well  as  more  conveniently. 

SUGAR-BEETS 

The  purpose  in  the  growth  of  sugar-beets  is  to  obtain 
the  largest  total  yield  of  sugar  to  the  acre ;  and  inasmuch 
as  the  sugar  content  of  the  beet,  as  well  as  its  right  growth 
and  development,  is  very  largely  influenced  by  the  char- 
acter of  the  fertilization,  this  matter  becomes  of  very 
considerable  importance,  in  view  of  the  promising  devel- 
opment of  the  sugar-beet  industry  in  this  country.  Thus 
far,  information  concerning  the  use  of  fertilizers  is  derived 
largely  from  the  results  obtained  in  other  countries, 
where  it  has  been  a  prominent  crop,  and  where  great 
attention  has  been  paid  to  this  factor  in  its  production. 

The  demands  of  the  crop  for  plant-food. 

The  sugar-beet  draws  heavily  upon  the  soil  for  the 
nitrogen  and  potash  constituents.  A  minimum  yield  of 
10  tons  of  topped  beets  contains  44  pounds  of  nitrogen, 
20  of  phosphoric  acid  and  96  of  potash.  On  medium, 
loamy  soils,  which  by  their  character  are  well  adapted 
for  the  growth  of  the  sugar-beet,  heavy  fertilization 
with  potash,  however,  has  not  been  found  to  be  desirable ; 
while  on  light  soils,  which  are  also  well  adapted  for  the 
crop,  liberal  manuring  with  potash  becomes  absolutely 
necessary. 

As  in  this  crop,  the  object  of  the  growth  is  to  secure 


344  Fertilizers 

not  primarily  beets,  but  sugar,  and  since  the  sugar  for- 
mation is  not  perfected  until  the  absorption  of  the  neces- 
sary food  from  the  soil  has  been  in  large  part  completed, 
any  fertilization  which  promotes  a  too  rapid  or  too  long- 
continued  growth  has  a  tendency  to  reduce  the  percentage 
of  sugar;  and  inasmuch  as  the  maturation  takes  place 
largely  in  the  months  of  early  fall,  the  growth  must  be 
forced  early  in  the  season.  That  is,  it  is  essential  that  a 
large  and  rapid  leaf  growth  be  made  early,  in  order  that 
the  food  from  the  air  may  be  acquired.  It  has  been  demon- 
strated that  for  this  early  and  rapid  growth  of  the  beet, 
phosphoric  acid  is  one  of  the  most  essential  constituents, 
which  explains  the  need  for  phosphoric  acid  in  larger  pro- 
portion than  is  indicated  by  the  composition  of  the  beet. 
The  crop  requires  a  considerably  greater  supply  of  phos- 
phoric acid  at  this  stage  of  its  growth  than  other  farm 
crops  which  are  quite  as  exhaustive,  and  it  is  also  evident 
that  in  order  that  the  crop  may  obtain  the  phosphoric 
acid  at  this  period,  it  must  be  soluble  and  immediately 
available;  hence  the  larger  portion  of  this  element 
applied  should  be  derived  from  superphosphates.  In 
the  matter  of  fertilization  with  nitrogen,  the  object  of 
the  growth  must  also  be  kept  in  view.  An  application 
which  would  encourage  steady  and  continuous  growth, 
rather  than  an  early  and  rapid  growth,  while  contributing 
to  a  large  yield,  causes  a  reduction  in  the  sugar  content 
of  the  beet.  Hence  it  is  strongly  urged  by  those  who  are 
in  a  position  to  give  sound  advice,  that  the  early  nitrogen 
fertilization  should  consist  of  the  quickly  available  forms, 
nitrate  or  ammonia,  and  that  the  organic  or  slower-acting 
forms  should  not  be  applied  in  such  excess  as  to  encourage 
a  late  growth.  Hence  it  is,  that  upon  medium  and  light 
lands  the  use  of  commercial  fertilizers  has  proved  of  greater 


Fertilizers  for  Various  Special  Crops  345 

service  in  the  growing  of  this  crop  than  the  exclusive  use 
of  yard  manure,  and  in  such  quantities  as  to  supply  the 
entire  needs  of  the  plant.  In  the  use  of  fertilizer,  not 
only  the  total  supply  of  the  constituents,  but  their  form, 
may  be  regulated  to  the  needs  under  different  conditions, 
thus  permitting  a  full  feeding  of  the  plant,  and  at  a  time 
most  suitable  to  accomplish  the  object  in  view,  — advan- 
tages which  are  not  possessed  by  the  natural  manures. 

A  fertilization  which  would  meet  the  needs  both  in 
respect  to  quantity  and  kind  of  fertilizers  may  be  as 
follows : 

On  good  soils,  the  application  of  a  fertilizer  contain- 
ing from  40  to  50  pounds  of  nitrogen,  from  50  to  60  of 
phosphoric  acid  and  from  40  to  50  of  potash  would  be 
sufficient  to  meet  the  demands  of  the  plant.  The  nitro- 
gen supplied  should  be  derived  largely  from  nitrates  or 
ammonia,  or  both,  and  the  phosphoric  acid  from  a  super- 
phosphate, while  the  potash  may  be  derived  from  sulfate 
or  muriate  of  potash.  The  former  is  preferable  if  applied 
during  the  spring  preceding  the  planting  of  the  beets. 
While  it  is  frequently  desirable,  for  convenience  and 
economy  of  labor  in  applying,  that  the  fertilizer  should 
be  mixed,  in  order  to  prevent  any  waste  of  soluble  nitro- 
gen, it  should  be  applied  in  fractional  dressings.  For 
example,  a  mixture  of  250  to  300  pounds  of  nitrate  of 
soda  (or  the  nitrogen  may  be  derived  partly  from  nitrate 
and  partly  from  ammonia),  400  to  500  pounds  superphos- 
phate and  80  to  100  of  muriate  or  high-grade  sulfate  of 
potash  should  be  applied  in  two  or  three  dressings.  A 
part  only  should  be  applied  previous  to  sowing,  for  both 
the  nitrate  and  the  potash  salts  have  a  depressing  effect 
upon  germination.  They  are  preferably  applied,  say, 
one-third  of  the  mixture  as  soon  as  the  plants  have  come 


346  Fertilizers 

up,  another  third  immediately  after  or  before  the  first 
cultivation,  and  the  remainder  immediately  after  or  before 
the  second  cultivation.  The  application  of  the  fertilizers 
in  these  forms  and  at  the  times  indicated  insures  the  rapid 
and  early  growth  and  development  of  the  plant;  and  by 
reason  of  the  solubility  of  the  nitrates  and  ammonia  salts, 
a  late  feeding  of  the  plant  with  nitrogen  is  obviated. 

On  light  or  medium  soils,  the  amount  of  plant-food 
should  be  increased  by  at  least  one-third,  though  frac- 
tional applications  should  be  made  as  previously  recom- 
mended. On  soils  rich  in  vegetable  matter,  a  part  of  the 
nitrogen  may  be  omitted,  though  the  phosphoric  acid 
should  not  be  reduced. 

The  influence  of  previous  deep  cultivation  of  soil. 

Another  point  to  observe  in  the  growing  of  beets  for 
sugar  —  and  it  also  has  an  immediate  bearing  upon 
fertilization  —  is  the  character  of  the  previous  cultiva- 
tion. If  the  soils  have  not  been  deeply  and  well  culti- 
vated, so  large  a  dressing  as  is  here  recommended  would 
be  likely  to  be  deleterious,  as  with  a  shallow  and  poorly 
prepared  soil  plants  would  have  less  opportunity  to  pene- 
trate deeply,  and  thus  too  great  a  growth  above  the  sur- 
face of  the  ground  would  be  encouraged,  with  a  consequent 
lowering  of  sugar  content  as  well  as  yield. 

The  best  practice  in  this  country  will  have  to  be  devel- 
oped by  the  experience  of  our  own  growers,  although  in 
the  absence  of  such  experience  the  recommendations 
here  made  may  be  relied  upon.  In  many  sections  in 
which  soils  and  climate  are  well  adapted  for  the  sugar- 
beet,  the  needs  as  yet  are  quite  as  much  for  improved 
methods  of  cultivation  as  for  added  fertility.  They  have 
not  been  exhausted  of  their  essential  fertility. 


Fertilizers  for  Various  Special  Crops  347 

SUGAR-CANE 

Another  special  crop,  confined  largely  to  one  state, 
Louisiana,  is  sugar-cane,  and  perhaps  no  other  one  crop 
has  in  this  country  received  such  careful  study  in  refer- 
ence to  its  needs  for  plant-food.  The  Sugar  Experiment 
Station  of  that  state  has  for  twelve  years  conducted  a 
series  of  systematic  experiments  designed  to  answer  the 
questions  as  to  what  the  needs  are  for  nitrogen,  phos- 
phoric acid  and  potash ;  and  the  results  of  this  work  thus 
far  secured  furnish  suggestions  in  reference  to  fertiliza- 
tion, which  will,  if  carefully  followed,  undoubtedly  result 
in  the  production  of  better  crops  than  are  grown  under 
present  systems.  Fertilizers  are  clearly  needed,  and  their 
right  use  is  a  profitable  practice,  though,  as  stated  by 
Doctor  Stubbs,  "many  ascribe  the  failure  from  their  use 
to  the  worthlessness  of  the  fertilizer,  when  it  should  be 
ascribed  to  some  defection  of  the  soil,  rendering  it  incapable 
of  appropriating  the  applied  fertilizer." 

The  chief  conclusions  in  reference  to  fertilizers  for 
sugar-cane  in  Louisiana,  so  clearly  set  forth  by  Doctor 
Stubbs  in  this  report,1  are  here  summarized,  as  it  is  be- 
lieved that  the  underlying  principles  are  applicable  else- 
where, though  naturally  their  use  must  be  modified  to 
suit  individual  cases. 

The  needs  of  the  plant  as  indicated  by  the  Louisiana  experi- 
ments. 

"An  examination  of  the  cane  plant  shows  that  a  crop 
of  30  tons  will  remove,  in  round  numbers,  102  pounds  of 
nitrogen,  45  of  phosphoric  acid  and  65  of  potash.  It  is, 
therefore,  a  relatively  exhaustive  crop,  and  unless  the 

1  "  Sugar-cane,"  Vol.  I,  Sugar  Experiment  Station,  Audubon 
Park,  New  Orleans,  La. 


348  Fertilizers 

physical  conditions  are  perfect,  even  good  soils  should 
receive  considerable  dressings  of  the  constituents,  if  the 
fertility  is  to  be  maintained. 

"The  results  secured  thus  far  in  the  experiments 
referred  to  demonstrate  that  the  soil  needs  nitrogen 
and  phosphoric  acid  particularly,  in  order  to  grow  cane 
successfully,  while  thus  far,  no  results  of  any  character, 
either  in  the  increased  sugar  content  or  tonnage  per  acre, 
have  been  visible  from  the  use  of  any  form  of  potash  upon 
the  alluvial  lands  of  the  lower  Mississippi.  Several  forms 
of  potash,  notably  the  carbonate,  and  ashes  of  cotton-seed 
hulls,  have  rather  decreased  the  yield  of  cane  and  injured 
the  physical  qualities  of  the  soil  by  causing  it  to  'run 
together.' 

"In  reference  to  the  form  and  amount  of  nitrogen, 
it  has  been  shown  that  sulfate  of  ammonia  gives  slightly 
better  results  than  any  other  form,  though  its  higher  cost 
gives  no  advantage  over  those  costing  less,  while  cotton- 
seed meal  comes  next,  followed  by  dried  blood  and  nitrate 
of  soda.  In  reference  to  the  amount  of  nitrogen  to  be 
applied,  it  is  shown  that  not  less  than  24  pounds  nor  more 
than  48  pounds  to  the  acre  should  be  applied.  Naturally, 
different  soils  and  different  kinds  of  cane  would  vary  in 
their  requirements  for  this  element,  and  the  amount 
needed  would  also  be  influenced  by  the  method  of  growing 
the  crop  :  whether  upon  '  succession'  land  —  that  is,  upon 
soils  upon  which  a  crop  of  stubble  cane  has  just  been 
taken  off,  and  which  has  been  in  cane  for  a  number  of 
years  without  the  intervention  of  a  leguminous  crop  be- 
tween to  restore  the  nitrogen  —  or  whether  upon  pea- 
vine  land,  upon  which  the  plant  cane  is  grown  the  first 
year,  stubble  cane  the  second,  and  corn  and  cowpeas  the 
third  year.  This  system  of  rotation,  which  introduces  a 


Fertilizers  for  Various  Special  Crops  349 

leguminous  crop  into  it,  not  only  improves  the  physical 
quality  of  the  soil,  but  enables  a  considerable  accumula- 
tion of  nitrogen,  frequently  over  one  hundred  pounds  per 
acre.  The  pea-vine  lands,  put  in  plant  cane  on  account 
of  their  excellent  physical  condition,  not  only  yield  up 
readily  the  nitrogen  stored  up  by  the  pea,  but  can  also 
assimilate  larger  quantities  of  plant-food  applied  as 
fertilizer.  Hence,  such  cane  usually  makes  large  crops. 
Since  nitrogen  is  the  chief  ingredient  taken  from  the  soil 
by  a  crop  of  cane,  it  follows  that  with  each  successive 
crop  of  cane  grown  on  the  land  without  the  interjection 
of  the  leguminous  nitrogen  there  arises  an  increased  de- 
mand for  nitrogen.  Hence,  stubble  cane  requires  larger 
quantities  than  plant  cane,  and  the  older  the  stubble, 
the  larger  its  requirements  for  this  element." 

In  reference  to  phosphoric  acid,  the  results  so  far 
indicate  positively  the  value  of  this  element  in  fertilizers 
for  sugar-cane  on  these  soils,  but  the  demand  for  this 
ingredient  is  small  in  comparison  to  that  for  nitrogen, 
36  pounds  to  the  acre  being  ample  for  the  crop.  The 
results  further  show  that  the  soluble  forms  of  phosphoric 
acid  are  preferred.  Inasmuch  as  the  leguminous  crop 
does  not  add  to  the  store  of  phosphoric  acid  in  the  soil, 
it  is  equally  needed  by  both  plant  and  stubble  cane. 

While  potash  has  not  been  shown  to  be  needed  on 
the  land  upon  which  the  experiments  were  conducted, 
because  of  the  abundance  of  potash  contained  in  the 
soil,  after  continuous  cropping  of  these  and  on  lighter 
soils  this  element  should  be  included  in  the  fertilizer. 

The  application  of  fertilizers. 

For  plant  cane,  a  small  quantity  of  readily  available 
fertilizer  directly  under  and  near  the  cane  is  highly 


350  Fertilizers 

beneficial,  as  it  provides  food  also  for  the  sucker,  which, 
with  food  at  hand,  is  greatly  aided  in  developing  a  healthy 
sucker,  and  thus  the  entire  plant  is  given  a  vigorous  send- 
off  in  youth.  It  is  necessary,  to  give  a  good  start  to  a 
young  plant,  to  withhold  manures  until  a  stand  is  secured, 
though  when  cane  is  planted  during  the  fall  and  winter, 
as  it  is  in  Louisiana,  the  danger  of  loss  by  leaching  must 
be  reckoned  upon,  and  the  exact  amounts  to  be  applied 
at  that  time  regulated  by  the  judgment  of  the  planter. 
Usually  the  more  perfect  the  incorporation  of  a  manure 
in  the  soil,  the  better  the  results  to  be  expected,  but  in  this 
case  it  should  be  deposited  in  a  drill  and  well  mixed  with 
the  soil.  In  the  spring,  after  the  cane  is  closely  off-barred, 
the  fertilizer,  if  not  applied  at  planting,  should  be  scat- 
tered on  both  sides  of  the  plant  from  the  center  of  the  row 
to  the  off-barred  furrow.  Thus,  in  reversing  the  furrow, 
the  manure  is  covered,  and  subsequent  cultivation  will 
mix  the  latter  with  the  soil.  If  the  cane  has  received  the 
first  application  at  planting,  the  second  one  should  be 
given  in  May,  on  both  sides  of  the  row.  The  stubble 
cane  should  not  be  fertilized  very  long  before  each  sprout 
has  sent  out  its  own  rootlets,  since  prior  to  this  no  good 
could  be  accomplished,  and  there  would  be  a  waste  of 
manure. 

HOPS 

Little  interest  has  been  taken  in  the  matter  of  ferti- 
lizers for  hops  because  they  are  grown  largely  upon  very 
rich  soils  in  the  West  where  little  fertilizer  is  used,  while 
in  the  East  the  interest  in  hop-culture  is  decreasing. 
Farm  manure  is  at  present  the  standard  fertilizer,  but 
many  growers  are  now  beginning  to  use  commercial  fer- 
tilizers. In  the  fertilizing  of  hops,  the  quality  of  the 


Fertilizers  for  Various  Special  Crops  351 

product  is  an  important  consideration,  and  an  excess  of 
available  nitrogen  which  is  liable  to  cause  a  too  rank 
growth  and  green  hops  of  an  undesirable  quality  should 
be  avoided .  Hence,  600  to  800  pounds  of  th  e  following  mix- 
ture would  supply  sufficient  plant-food  in  the  right  forms : 

Nitrate  of  soda 50  Ib. 

Dried  blood 100  Ib. 

Tankage 200  Ib. 

Acid  phosphate 450  Ib. 

Muriate  of  potash 200  Ib. 

FLAX 

Flax  is  a  peculiar  crop  to  feed  because  it  has  a  very 
fine  tap  root  and  few  root-hairs,  and  because  it  makes  its 
growth  in  a  relatively  short  period  of  time,  forty  or  fifty 
days,  it  is  often  termed  a  dainty  feeder.  Few  investi- 
gations have  been  made  to  determine  the  best  kinds  and 
amounts  of  plant-food  to  use.  The  practice  of  successful 
growers  seems  to  show  that  liberal  applications  of  manure 
or  the  use  of  green-manure  for  two  or  more  seasons  sup- 
plemented with  nitrate  of  soda  as  needed  gives  satisfactory 
results.  In  the  absence  of  farm  manure  or  green-manure, 
300  to  400  pounds  of  a  mixture  made  as  follows  should 
supply  sufficient  amounts  of  the  elements,  though  nitrate 
of  soda  may  still  be  used,  as  needed,  as  a  top-dressing : 

Nitrate  of  soda 250  Ib. 

Dried  blood 100  Ib. 

Acid  phosphate 500  Ib. 

Muriate  of  potash 150  Ib. 

MISCELLANEOUS  CROPS 

Other  crops  of  importance  for  which  the  need  of  fer- 
tilizers is  frequently  apparent  include  sorghum,  buck- 


352  Fertilizers 

wheat,  peanuts,  roses  and  herbaceous  plants,  lawns, 
grasses  and  plant-house  vegetables.  These  are,  of  course, 
similar  to  those  already  described,  since  their  best  devel- 
opment requires  that  they  shall  be  well  supplied  with  the 
fertilizing  constituents,  nitrogen,  phosphoric  acid  and 
potash,  though  their  special  needs  in  this  respect  have  not 
been  so  fully  investigated  as  the  other  crops  dealt  with 
in  this  chapter.  The  discussion  of  their  requirements  is, 
therefore,  necessarily  brief,  and  the  suggestions  made 
are  of  a  general  rather  than  a  special  character,  though 
they  may  serve  as  a  safe  guide. 

Sorghum. 

Sorghum  is  grown  both  for  forage  and  for  sugar,  and 
its  fertilization  should  be  discussed  from  these  two  stand- 
points. If  grown  for  forage,  the  fertilization  should  be 
more  liberal  and  of  a  different  character  than  if  for  sugar, 
as  the  object  is  the  largest  yield  of  succulent  food  rather 
than  the  highest  yield  of  sugar,  and  the  yield  of  sugar  is 
not  always  consistent  with  the  highest  yield  of  cane. 
For  forage,  therefore,  the  fertilizer  recommended  for 
maize  forage  (p.  262)  is  well  adapted  for  sorghum  on  soils 
in  a  good  state  of  fertility,  though  since  the  plant  is  very 
slow  to  start,  its  early  growth  is  stimulated  if  a  larger 
amount  of  readily  available  nitrogen  is  used  than  is  de- 
sirable for  corn,  particularly  on  soils  of  medium  fertility, 
and  which  have  not  been  previously  well  fertilized.  If 
grown  for  sugar,  too  much  nitrogen  must  be  avoided, 
since  an  excess  of  this  element  in  the  fertilizer  causes  an 
imperfect  ripening,  and  consequently  a  higher  percent- 
age of  non-cry stallizable  sugar  in  the  cane;  though  if 
quickly  available  forms  are  used,  as  nitrate,  ammonia 
or  dried  blood,  which  may  be  absorbed  by  the  plant 


Fertilizers  for  Various  Special  Crops  353 

early  in  the  season,  a  larger  amount  may  be  applied  with 
safety  than  if  the  poorer  forms  are  used.  Of  the  three 
constituents,  potash  in  the  form  of  muriate  seems  to  be 
the  one  exercising  the  greatest  influence  upon  the  yield  of 
sugar,  hence  it  should  always  be  introduced  in  consid- 
erable amounts  in  fertilizers  for  sorghum.1  A  fertilizer 
furnishing  20  pounds  of  nitrogen,  35  of  phosphoric  acid 
and  60  of  potash  to  the  acre  will  meet  the  needs  on  aver- 
age soils. 

Buckwheat. 

Buckwheat  is  frequently  grown  upon  the  poorer  soils 
of  the  farm.  It  is  a  crop  well  adapted  to  mountain  lands, 
and  as  a  preparatory  crop  in  the  breaking  of  new  lands. 
It  has  not  been  carefully  studied  in  reference  to  its  needs 
for  plant-food,  though  phosphoric  acid  seems  to  be  the 
constituent  more  particularly  required  than  the  others. 
Its  need  of  nitrogen  is  marked,  yet  because  its  entire  growth 
and  development  are  made  during  the  months  of  July  and 
August,  when  conditions  are  most  favorable  for  soil 
activities,  heavy  nitrogenous  fertilization  is  not  to  be 
recommended,  except  when  grown  on  very  light  soils,  or 
those  deficient  in  vegetable  matter.  The  moderate  use 
of  fertilizers  rich  in  minerals,  and  which  contain  nitrogen 
in  quickly  available  forms,  result  favorably,  not  only  in 
increasing  the  yield,  but  assist  materially  in  maturing 
the  crop,  a  matter  of  great  importance.  A  fertilization 
with  25  pounds  to  the  acre  each  of  phosphoric  acid  and 
potash  and  10  of  nitrogen  may  be  regarded  as  a  good  one 
for  soils  of  medium  character. 

1  Report  for  1886,  New  Jersey  Agricultural  Experiment 
Station. 

2A 


354  Fertilizers 

Peanut. 

The  peanut  is  a  leguminous  plant,  and,  like  others  of 
this  family,  is  not  specifically  benefited  by  nitrogen, 
but  responds  readily  to  liberal  dressings  of  phosphoric 
acid  and  potash.  The  fertilization  suggested  for  green- 
manure  crops,  namely,  a  mixture  of  three  parts  acid 
phosphate  and  one  part  muriate  of  potash,  or  equal 
parts  of  acid  phosphate  and  kainit,  may  be  used  for 
this  crop  with  great  advantage.  The  applications,  if 
frequently  made,  need  not  exceed  300  to  400  pounds 
to  the  acre.  Like  other  leguminous  crops,  it  is  specifically 
benefited  by  lime,  medium  dressings  of  which  (20  bushels 
to  the  acre)  should  be  made  at  least  once  in  four  years. 
In  the  districts  in  which  this  crop  is  successfully  grown, 
lime  marls  are  frequently  obtainable  at  slight  expense, 
and  may  be  used  with  great  advantage. 

Roses  and  other  flowering  plants. 

In  the  growing  of  roses  and  other  herbaceous  plants, 
of  which  the  flowers  constitute  the  crop,  great  care  is 
usually  taken  in  the  preparation  of  the  soil,  and  natural 
soils  are  seldom  used.  Notwithstanding  the  richness  of 
the  prepared  soils,  the  crops  are  benefited  by  the  addition 
of  commercial  fertilizers,  particularly  those  phosphatic 
in  their  nature.  Ground  bone  is  especially  useful,  since 
it  furnishes  both  nitrogen  and  phosphoric  acid  in  slowly 
available  f onns,  and  usually  sufficient  nitrogen  to  meet  the 
needs  of  the  plant,  as  excessive  quantities  of  this  element 
cause  a  too  vigorous  and  rank  growth  of  foliage,  which  is 
not  accompanied  by  profuse  flowering.  A  good  mixture 
for  the  prepared  soils,  therefore,  may  consist  of  four  parts 
of  ground  bone  and  one  part  of  muriate  of  potash,  which 


Fertilizers  for  Various  Special  Crops  355 

may  be  applied  at  the  rate  of  four  pounds  to  the  square 
rod  of  area,  and  well  worked  into  the  soil  previous  to  set- 
ting the  plants.  The  after  fertilization  may  contain  a 
larger  portion  of  the  soluble  phosphoric  acid,  which  is 
more  readily  distributed.  The  need  for  nitrogen  is  indi- 
cated by  a  yellow,  rather  than  a  bright  green,  color  in  the 
foliage.  Nitrogen  may  be  supplied  by  light  dressings 
(i  to  1  pound  to  the  square  rod)  of  the  active  forms  of 
this  element,  preferably  nitrate  of  soda,  because  of  its 
ready  distribution.  In  the  preparation  of  soils  for  these 
plants  in  the  house,  the  mixture  may  be  applied  at  the 
rate  of  2  pounds  for  every  100  square  feet  of  surface,  the 
after  application  to  consist  of  the  more  soluble  forms  as 
recommended  for  the  hardy  plants.  An  even  mixture  of 
nitrate  of  soda  and  acid  phosphate  may  be  used  at  the 
rate  of  one  pound  for  every  100  square  feet  of  surface 
once  in  two  weeks,  if  the  plants  do  not  show  vigorous 
growth. 

Lawn  grasses. 

The  fertilization  of  lawns  is  also  important  in  a  sense, 
because  proper  fertilizing  obviates  the  necessity  of  the 
home  manures,  which,  although  excellent  as  sources  of 
the  constituents,  are  frequently  offensive.  The  use  of 
manure  also  involves  considerable  labor,  both  in  the  ap- 
plication and  the  consequent  removal  of  the  coarse  part 
in  the  spring,  besides  resulting  in  the  introduction  of 
weed  seeds.  In  the  preparation  of  the  soil  for  a  lawn, 
it  must  be  supplied  with  an  abundance  of  all  of  the  neces- 
sary fertilizer  ingredients  previous  to  seeding,  and  of  these 
phosphoric  acid  and  nitrogen  are  especially  important. 
Too  great  an  excess  of  potash  encourages  the  development 
of  the  clovers  rather  than  the  grasses.  This  preparatory 


356  Fertilizers 

fertilizer  may  contain  the  more  slowly  available  forms 
of  nitrogen  and  phosphoric  acid.  Ground  bone  is  an 
excellent  source  of  these  elements,  and  a  mixture  of  five 
parts  of  ground  bone  and  one  of  muriate  of  potash  makes 
an  excellent  dressing.  This  may  be  applied  at  the  rate 
of  five  pounds  to  the  square  rod,  and  thoroughly  worked 
into  the  soil.  The  after-fertilization  may  consist  chiefly 
of  nitrogen,  preferably  as  a  nitrate,  since  its  ready  solu- 
bility permits  of  its  free  penetration  into  the  lower  layers, 
which  encourages  a  deeper  root  system,  and  thus  greater 
resistance  to  drought. 

The  top-dressings  with  nitrate  of  soda  should  con- 
sist of  light  fractional  dressings,  rather  than  of  large 
amounts  at  one  time.  One-half  pound  to  the  square 
rod,  twice  or  thrice  during  the  season,  —  the  first  as  soon 
as  the  grass  is  well  started  in  the  spring,  and  preferably 
immediately  preceding  a  rain,  —  will,  if  the  land  has  been 
previously  prepared  well,  be  sufficient.  To  facilitate 
the  distribution  of  the  nitrate,  as  well  as  to  supply  a  suffi- 
cient abundance  of  phosphoric  acid,  it  may  be  mixed  with 
equal  parts  of  ground  bone. 

Forcing-house  crops. 

A  rich  garden  loam,  to  which  a  considerable  pro- 
portion of  stable  manure  —  one-third  to  one-half  the 
bulk  —  has  been  added,  is  the  usual  type  of  soils  for 
such  crops  as  tomatoes,  lettuce,  radishes  and  cucumbers 
under  glass.  The  addition  of  fertilizers  to  these  is  seldom 
advisable.  It  has  been  demonstrated,  however,  that  such 
mixtures  are  not  essential,  and  that  the  crops  may  be 
profitably  and  successfully  grown  in  mediums  which 
contain  no  plant-food,1  if  supplied  with  an  abundance  in 

1  Connecticut  State  Experiment  Station  Reports  for  1895, 
1896  and  1897. 


Fertilizers  for  Various  Special  Crops  357 

available  forms  from  artificial  sources.  In  the  absence 
of  good  manure,  which  is  the  chief  expense,  a  reasonably 
fertile  loamy  soil  may  be  used  for  filling  the  beds,  in  which 
at  the  time  of  filling  may  be  mixed,  for  each  100  square 
feet  of  surface,  one-half  pound  of  nitrate  of  soda,  one 
pound  of  acid  phosphate,  one  pound  of  ground  bone  and 
one-half  pound  of  muriate  of  potash.  This  application 
will  be  sufficient  to  supply  the  needs  of  the  plants  for  food 
until  growth  is  well  started,  after  which  they  should  be 
fertilized  at  least  once  each  week  with  one-quarter  of  a 
pound  of  nitrate  of  soda  for  every  100  square  feet  of 
surface  area,  and  with  the  mineral  fertilizers  at  the  rate 
of  one  pound  of  acid  phosphate  and  one-half  pound  of 
muriate  of  potash  every  two  weeks.  These  may  be  ap- 
plied in  solution,  or  evenly  distributed  over  the  surface 
of  the  soil,  and  worked  in  before  watering.  The  amounts 
to  apply  should  always  be  governed  by  the  judgment  of 
the  grower.  There  is  less  danger  from  the  application 
of  too  much,  if  properly  used,  than  is  commonly  supposed. 


INDEX 


Agricultural  salt,  115. 

Agricultural  value  of  fertilizer,  178. 

Air-slaked  lime,  139. 

Alfalfa,  273. 

Ammonia,  47 ;  sulfate,  48 ;  cal- 
cium cyanamid,  49 ;  ammonium 
nitrate,  53. 

Ammonite,  39. 

Ammonium  nitrate,  53. 

Analysis,  see  chemical  analysis  of 
fertilizers,  175-188;  of  plants, 
208. 

Animal  bone,  62 ;  raw,  63. 

Animal  charcoal,  67. 

Animal  matter,  39. 

Apatite,  71. 

Apples,  314. 

Application  of  fertilizers,  204;  of 
lime,  148 ;  of  manures,  124. 

Apricots,  325. 

Artificial  fertilizers:  history  of  their 
use,  27 ;  need  of,  28 ;  made  neces- 
sary by  increase  in  cost  of  labor, 
28;  by  demands  for  special 
crops,  30;  by  inadequacy  of 
farm  manures,  31 ;  by  demands 
of  increased  fruit  production,  32 ; 
do  artificial  fertilizers  pay  ?  33 ; 
unprofitable?  34. 

Ashes:  coal,  112;  corn  cob,  113; 
cotton  hull,  113;  tan  bark,  111; 
wood,  111. 

Asparagus,  314. 

Availability :  different  forms  of 
nitrogen,  53 ;  tables,  56 ;  con- 
ditions which  modify  availability, 
57. 

Azotin,  39. 

Barley,  223 ;    and  peas,  266. 
Basic  fertilizer:  for  market  garden, 
287;   for  fruits,  313. 


Basic  slag,  72 ;  artificial  basic  slag 
meal,  73. 

Bat  guano,  46. 

Beans,  258,  296. 

Beets,  fertilizer  constituents  in,  16 ; 
for  fodder,  280;  for  market 
garden  crop,  289 ;  beet  tops,  294. 

Bermuda  grass,  269. 

Berries  (see  Orchard  fruits,  308) ,  326. 

Blackberries,  328. 

Blood,  dried,  37;  red,  38;  avail- 
ability, 56. 

Bone  ash,  68;  commercial  grades, 
65;  boiled,  64;  fine,  63;  phos- 
phate, 62;  raw,  63;  steamed,  64; 
tankage,  66. 

Bone  meal:  availability  of  nitro- 
gen in,  56. 

Broccoli,  293. 

Brussels  sprouts,  293. 

Buckwheat,  353. 

Bulb  crops,  market  garden,  29. 

Cabbage :  green  forage,  277 ;  mar- 
ket garden,  293. 

Calcium,  see  Lime  and  calcium 
compounds,  135. 

Calcium  carbide  waste,  117;  cyan- 
amid, 49 ;  magnesium  lime,  138 ; 
nitrate,  52;  sulfate,  116,  144. 

Calculation  of  commercial  value  of 
fertilizers,  187. 

Carbonate  of  potassium,  99 ;  double, 
98. 

Carnallit,  96. 

Carrots:  fertilizer  constituents  in, 
16;  forage  crop,  280;  market 
garden,  289. 

Castor  pomace,  44. 

Cauliflower,  293. 

Celery,  295 ;  fertilizer  constituents 
in,  16. 


359 


360 


Index 


Cereals,  200,  212;  experiments  to 
determine  lacking  elements  in 
soil,  214;  importance  of  system, 
219;  crops  in  rotation,  220; 
Indian  corn,  220;  oats,  222; 
barley,  223;  wheat,  224  (con- 
tinuous wheat,  232) ;  rye,  225 ; 
clover,  225;  timothy,  226;  gain 
of  fertility  through  rotation,  228 ; 
necessity  of  excess  plant-food, 
229 ;  single  crop  system,  231 ; 
meadows,  234 ;  fertilizing  pays, 
236 ;  green  forage,  260 ;  fertilizer 
constituents  in,  16. 

Charcoal,  animal,  67. 

Chemical  analyses  of  fertilizers,  the 
interpretation  of,  175;  agricul- 
tural value,  178;  commercial 
value,  179 ;  example,  180 ;  how 
obtained,  181 ;  schedule,  182 ; 
calculation  of  commercial  value, 
187 ;  uniformity  of  manufactured 
brands,  188 ;  see  Guarantee ;  Pur- 
chase of  fertilizers. 

Chemical  composition  of  superphos- 
phate, 90. 

Chemical  elements :  in  plants,  2, 
16 ;  in  soil,  3. 

Cherries,  325. 

Chicken  manure,  125. 

Chives,  291. 

Citrous  fruits,  325. 

Clay  soil,  imperfections  of,  194. 

Clovers :  characteristics,  201 ;  fer- 
tilization, 225 ;  green  forage,  269 ; 
green  manure,  130. 

Coal  ashes,  112. 

Cocoa  shells,  114. 

Collards,  293. 

Commercial  valuation  of  fertilizers : 
relative  value,  179 ;  illustration, 
180;  how  calculated,  181 ;  sched- 
ule of  trade  values,  182. 

Composts,  127. 

Corn-cob-ashes,  113. 

Corn :  exhaustive  of  fertility  ele- 
ments, 220;  fertilizer  constit- 
uents in,  16  ;  for  forage,  261. 

Corn,  sweet,  305. 


Cost  of  farming,  29. 

Cotton,      333;        formulas,      336; 

methods  of  application,  337. 
Cotton-seed  meal,  43. 
Cowpea  and  soybean,  271. 
Cranberries,  329. 
Crimson  clover,  see  Clovers. 
Crude  fish  scrap,  104. 
Cucumbers,  299. 
Currants,  329. 

Deficiencies  of  the  soil,  192. 
Derivation  of  a  soil,  192. 
Direct  manures,  22. 
Double  manure  salt,  98. 

Eggplant,  257,  297. 

Elements,  essential  of  a  fertilizer,  20. 

Extensive  farming,  199. 

Farm  labor,  28. 

Farm  manures,  see  Manures. 

Farm  practice,  irrational,  17. 

Farm  success,  1. 

Fertilizations,  systems  of,  204. 

Fertility :  definition,  2 ;  chemical 
elements  needed,  2 ;  influence  of 
water,  climate,  season,  3 ;  of 
physical  character  of  soil,  4 ;  of 
location  of  soil,  5 ;  practical 
fertility,  6 ;  potential  fertility,  6  ; 
loss  of  fertility,  8;  importance 
of  careful  culture,  9 ;  loss  of  ni- 
trogen, 9 ;  loss  of  mineral  ele- 
ments, 11;  artificial  losses,  13; 
sale  of  crops,  13 ;  improper 
handling  of  manures,  18. 

Fertility  elements  in  crops,  and 
prices  received  for  same,  14. 

Fertilizers  :  essential  elements,  20 ; 
natural  and  artificial,  21 ;  direct, 
indirect,  22 ;  available,  unavail- 
able plant-food,  23 ;  loss  of 
soluble  plant-food,  25  ;  usefulness 
not  dependent  on  source,  26 ; 
use  of  fertilizer,  historical,  27 ; 
need  of  artificial  fertilizer  through 
changed  conditions  of  farming, 
23-31 ;  farm  manures  inadequate, 


Index 


361 


31 ;    standard   high  grade  mate- 
rials, 153. 

Complete,  165;  purchase  of, 
165. 

Home  mixtures,  167 ;  raw  ma- 
terials, 168. 

Field  beans,  258. 

Field  truck  crops:  potatoes,  238; 
sweet  potatoes,  244 ;  tomatoes, 
248 ;  peppers,  257 ;  eggplant, 
257;  peas,  257;  beans,  257; 
field  beans,  258. 

Fish,  dried,  39  ;  ground,  39;  guano, 
39;  scrap,  104. 

Flax,  351. 

Florida  phosphate,  70. 

Flowering  plants,  354. 

Fodder  beets,  280. 

Forage  crops,  see  Green  forage. 

Forcing  house  crops,  354. 

Formulas  of  fertilizers,  169. 

Fruits,  see  Orchard  fruits. 

Garbage  tankage,  42. 

Garlic,  291. 

Gas  lime,  116. 

Gooseberries,  329. 

Grapes,  339. 

Grasses,  see  Cereals ;  character- 
istics, 200,  212;  fertilization, 
226;  green  forage,  260;  lawn, 
355. 

Green  forage  crops  — 

Cereals  and  grasses,  260 ;  maize 
corn,  261 ;  wheat  and  rye,  263 ; 
spring  rye,  264;  oats,  265;  oats 
and  peas,  266;  millet,  267;  or- 
chard grass,  267 ;  Italian  rye 
grass,  268 ;  Bermuda  grass,  269. 
Clovers  and  legumes:  Japan 
clover,  271 ;  cowpea  and  soy- 
bean, 271 ;  spring  vetch,  271 ; 
alfalfa,  273;  sweet  clover,  274; 
need  of  lime,  274. 

Soiling  crops,  275;  scheme  of 
practice  of  New  Jersey  Experi- 
ment Station,  276. 

Cabbage,  277;  rape,  278;  kohl- 
rabi, 279. 


Root  crops,  279  :  fodder  beets, 
sugar  beets,  carrots,  turnips  and 
swedes,  280-281. 
Tuber  crops,  282. 

Green-manures,  see  Manures. 

Green  sand  marl,  114. 

Ground  burned  lime,  139. 

Guano  :  bat,  46  ;  fish,  39  ;  natural, 
44 ;  Peruvian,  45  ;  Ichaboe,  46 ; 
phosphatic,  74. 

Guarantee  of  composition  of  fer- 
tilizer, 159 ;  see  Purchase  of 
fertilizers. 

Gypsum,  116,  144. 

Hair  waste,  43,  106. 

Hairy  vetch,  272. 

Hard  salt,  96. 

Herbs,  306. 

Herd  grass,  fertilizer  constituents 

in,  16. 

High-grade  mixtures,  169. 
Home  mixtures,  167. 
Hops,  350. 

Horn,  ground  or  meal,  42. 
Hydrated  lime,  139. 

Ichaboe  guano,  46. 
Intensive  farming,  199. 
Iron  phosphate,  72. 
Irrational  farm  practice,  17. 
Italian  rye  grass,  268. 

Japan  clover,  271. 

Kaini,  95 ;  on  sweet  potatoes,  244. 
Kale,  293. 
King  crab,  109. 

Land  phosphate,  69. 

Land  plaster,  144. 

Land  rock,  69. 

Lawn  grasses,  355. 

Leather  meal,  42. 

Leeks,  291. 

Legumes :  nitrogen  gatherers,  128 ; 
as  green-manures,  128-134 ;  green 
forage,  269;  liming  of  legumes, 
274. 


362 


Index 


Lemons,  325. 

Lettuce,  296;  fertilizer  constitu- 
ents in,  16. 

Lime :  lime  and  calcium  com- 
pounds, 135-152 ;  occurrence, 
136;  forms  on  market,  136; 
action  in  soil,  140;  mechanical 
effects,  141 ;  chemical  effects, 
142 ;  upon  organic  matter,  143 ; 
upon  potash,  143 ;  upon  phos- 
phates, 143 ;  biological  effects, 
145. 

Lime  analyses,  152. 

Lime:  forms  on  market,  caustic, 
136;  calcium  magnesium,  138; 
ground  burned  lime,  139;  hy- 
drated,  139;  air-slaked,  139; 
oyster  shell,  139 ;  shell  marl,  140. 
Use  of  lime,  146 ;  application, 
148 ;  form  to  use,  149 ;  its  cost, 
150;  legumes,  274;  fruit  trees, 
310. 

Limestone,  ground,  137. 

Linseed  meal,  44. 

Lobster  shells,  109. 

Low-grade  mixtures,  169. 

Lucerne,  alfalfa,  273. 

Maize,  261. 

"Makeweight,"  172. 

Manufactured  brands,  uniformity, 
188. 

Manures,  natural  vs.  artificial,  21 ; 
direct  and  indirect  effects,  20-22 ; 
inadequacy  of  farm  manure,  32. 

Farm  yard,  119-127;  advan- 
tages, 119;  variation,  120; 
sources  of  loss,  121 ;  proper  care, 
122;  preservatives,  122;  im- 
provement of,  123 ;  application, 
124;  poultry  and  chicken,  125; 
composts,  127. 

Green :  128-134 ;  'nitrogen 
gatherers  and  nitrogen  con- 
sumers, 128;  most  useful  crops, 
130;  mixtures,  132;  precau- 
tions, 133. 

Marble  lime,  138. 

Market-garden   crops:     conditions 


of     growth,     202,     283;      basic 

fertilizer,  287;    root  crops,  289; 

bulb  crops,  291 ;  cole  crops,  293 ; 

pot     herbs,    294;      salad,    295; 

pulse    crops,    296;     solanaceous 

crops,    297;     vine    crops,    299; 

miscellaneous,  300. 
Marl,  green  sand,  114;   shell,  140. 
Meadows,  234. 
Meal:      horn,     42;      leather,    42; 

cottonseed,  43 ;   linseed,  44. 
Menhaden,  105. 

Methods  of  use  of  fertilizers,  191. 
Millet,  267. 

Mineral  phosphates,  68. 
Mixed      fertilizers :        agricultural 

value,    178;     commercial   value, 

179;    calculation  of  values,  187; 

vs.  raw  materials,  165. 
Muck,  107. 
Muriate  of  potash,  96 ;  on  potatoes, 

242. 

Muskmelons,  299. 
Mussels,  109. 

Natural  fertility,  1-19;  see  Fer- 
tility. 

Nitrate  :  of  soda,  51 ;  ammonium, 
53 ;  calcium,  52 ;  potassium,  53. 

Nitrate  nitrogen,  50;  see  Nitrog- 
enous fertilizers. 

Nitrification,  50. 

Nitrogenous  fertilizers,  36-59;  defn. 
of  "form  of  nitrogen,"  36; 
dried  blood,  37  ;  dried  meat,  etc., 
39 ;  dried  fish,  39 ;  ground  fish, 
39 ;  fish  guano,  39 ;  tankage,  40 ; 
low-grade  products,  42;  vege- 
table nitrogenous  products,  43; 
cottonseed  meal,  43 ;  linseed 
meal,  44 ;  castor  pomace,  44 ; 
vegetable  pomaces,  44;  natural 
guanos,  44 ;  ammonia  com- 
pounds, 47 ;  sulfate  of  ammonia, 
48 ;  calcium  cyanamid,  49 ;  ni- 
trate nitrogen,  50;  nitrate  of 
soda,  51 ;  calcium  nitrate,  52 ; 
potassium,  53 ;  ammonium,  53 ; 
relative  availability  of  different 


Index 


363 


forms,     53;      conditions    which 

modify,  57. 
Nitrogen  gatherers,  128;   nitrogen 

consumers,  128. 
Nitrogenous  matter  in  phosphatic 

materials,  62  et  seq. 

Oats :  fertilizer  constituents  con- 
tained, 16;  in  rotation,  222 ;  green 
forage,  265. 

Oats  and  peas,  266. 

Okra,  306. 

Onions,  29. 

Oranges,  325. 

Orchard  fruits  and  berries:  differ 
from  general  farm  crops,  308; 
soil  considerations,  311;  fertiliz- 
ing in  general,  312;  apples,  and 
pears,  314 ;  peaches,  experiments 
and  results,  318 ;  plums,  cherries, 
apricots,  325;  citrous  fruits, 
325;  small  fruits,  326;  cran- 
berries, 329. 

Orchard  grass,  267. 

Organic  nitrogen :  defn.,  23,''  37 ; 
various  forms  in  use,  37-47; 
availability,  47. 

Oxy-acetylene  residue,  118. 

Oyster-shell  lime,  139. 

Palmaer  phosphate,  74. 

Parsnips,  fertilizer  constituents  in, 
16. 

Peaches,  318 ;  experiments  at  New 
Jersey  Experiment  station,  318. 

Peanuts,  354. 

Pears,  314. 

Peas :  field  truck,  258 ;  green  forage, 
266 ;  cowpea,  271 ;  market  gar- 
den, 296. 

Peat,  107. 

Pebble  phosphate,  70. 

Peppers,  257,  298. 

Peruvian  guano,  45. 

Phosphate  of  lime,  62,  81. 

Phosphates :  organic  substances, 
62  et  seq.;  mineral  phosphates, 
68  et  seq. ;  manufactured  phos- 
phates, 73;  sources  of  phos- 


phoric acid  to  plants,  75 ;  in- 
fluence of  source,  76;  of  fine- 
ness, 77 ;  of  character  of  soil,  77 ; 
of  kind  of  crop,  78 ;  general  use- 
fulness, 78;  comparison  with 
superphosphates,  85. 

Phosphatic  materials :  phosphate  of 
lime,  62;  bone  phosphate,  62; 
animal  phosphate,  62 ;  raw  bone, 
63;  boiled  steamed  bone,  64; 
commercial  grades  of  bone,  65; 
bone  tankage,  66 ;  bone  black, 
66;  animal  charcoal,  67;  bone 
ash,  68;  Florida  rock,  70 ;  Cana- 
dian apatite,  71 ;  Tennessee, 
71 ;  superphosphates,  81  et  seq. 

Phosphoric  acid  :  derivation,  61 ; 
in  animal  matter,  62 ;  guarantees 
and  grades,  65;  in  mineral 
matter,  68 ;  in  basic  slag,  72 ;  in 
manufactured  phosphates,  73 ; 
derived  by  plant  from  phosphates 
through  decay,  76;  conditions 
which  affect  availability,  76; 
forms :  insoluble,  81 ;  soluble, 
82,  84;  reverted,  82;  "free" 
phosphoric  acid,  91 ;  soluble  in 
water,  but  fixed  in  soil,  92. 

Phosphorus  powder,  117. 

Pigeon  manure,  46,  125. 

Plant-food,  available,  unavailable, 
23. 

Plaster,  land,  144. 

Plums,  328. 

Potash :  importance,  93 ;  avail- 
ability, 94. 

Forms:  crude  products,  96- 
100 ;  manufactured  products,  96 ; 
fixation  in  soil,  100. 

Sources  of:  kainit,  95;  hard- 
salt,  96;  carnallit,  96;  muriate, 
96;  high-grade  sulfate,  97; 
double  manure  salt,  98;  potash 
manure  salt,  98;  double  car- 
bonate of  potash  and  magnesia, 
98;  carbonate,  99;  nitrate,  99; 
feldspar,  99 ;  seaweeds,  100. 

Potatoes :  fertilizer  constituents  in, 
16 ;  in  crop  rotation,  209 ;  field 


364 


Index 


truck  crop,  238-244 ;  early,  238 ; 
formulas,  late,  243,  formulas, 
roughage,  282. 

Potential  fertility,  6. 

Poultry  manure,  46,  125. 

Powder  waste,  116. 

Power  of  plant  to  acquire  food,  199. 

Practical  fertility,  6. 

Previous  treatment  of  soil,  195. 

Prices  received  for  fertility  ele- 
ments in  crops  removed,  14. 

Pulse,  crops,  296. 

Pumpkins,  299. 

Purchase  of  fertilizers:  standard 
high-grade  materials,  154;  va- 
riable materials,  155 ;  unit  basis 
of  fertilizers,  157 ;  ton  basis  of 
fertilizers,  157 ;  guarantee  a 
necessity,  158 ;  relation  of  guar- 
antee to  selling  price,  159;  dis- 
cussion, 162;  raw  materials  vs. 
mixed  fertilizers,  165 ;  home 
mixtures,  167;  formulas,  169; 
general  advice,  173. 

Rape,  278. 

Raspberries,  326. 

Raw  bone,  63. 

Raw  material  vs.  mixed  fertilizers, 

165. 

Rhubarb,  304. 
River  phosphate,  69. 
River  rock  phosphate,  69. 
Rock  phosphates,  69. 
Root   crops :    characteristics,   202 ; 

for  green  forage,  279 ;  for  market 

garden,  289. 
Roses,  354. 
Rotation  of   crops,   209;    gain  in 

fertility  in  soil,  228. 
Rye,  225 ;  fertilizer  constituents  in, 

16 ;  forage  crop,  263 ;  spring  rye, 

264. 
Rye  grass,  Italian,  269. 

Salt,  115, 

Sandy  soils :  imperfections,  194. 
Seaweeds,  source  of  potash,  100, 110. 
Sewage,  107. 


Shallots,  291. 

Shell  marl,  140. 

Slag,  basic,  72 ;  meal,  73. 

Soda,  nitrate  of,  see  Nitrate. 

Soft  phosphate,  70. 

Soil  fertility,  see  Fertility. 

Soiling  crops,  275. 

Soils:  derivation,  guide  to  possible 
imperfections,  192 ;  clay,  194 ; 
sandy,  194  ;  influence  of  previous 
treatment,  195. 

Solanaceous  crops,  297. 

Soluble  plant-food,  danger  of  loss, 
25. 

Sorghum,  352. 

South  Carolina  rock  phosphates,  69. 

Soybean  and  cowpea,  271. 

Spinach,  294. 

Spring  vetch,  272. 

Squash,  299. 

Standard  high-grade  materials,  153. 

Strawberries,  326. 

Sugar  beets,  280,  343-347. 

Sugar  cane,  347 ;  Louisiana  experi- 
ments, 347. 

Sulfate  of  ammonia,  48. 

Sulfate  of  lime  see  Gypsum. 

Sulfate  of  potash,  97 ;  on  potatoes, 
242. 

Superphosphates,  61,  82;  process 
of  manufacture,  83 ;  differences 
in  superphosphates,  84 ;  phos- 
phates vs.  superphosphates,  85; 
reversion,  87 ;  double  superphos- 
phates, 89:  "total  available," 
89 ;  chemical  composition,  90. 

Swedes,  281. 

Sweet  corn,  305. 

Sweet  potatoes,  244-248;  rough- 
age, 282. 

Systems  of  fertilizing:  1.  based 
upon  the  influence  of  a  single 
element,  204 ;  2.  based  upon 
need  of  abundant  supply  of  min- 
erals, 205 ;  see  also  "  Use"  of  fer- 
tilizers. 

Tanbark  ashes,  111. 

Tankage,  40 ;  garbage,  42 ;  bone,  66. 


Index 


365 


Tennessee  phosphate,  71. 

Tetracalcic  phosphoric  acid,  83. 

Thomas  phosphate  powder,  72. 

Timothy,  226;  fertilizer  constit- 
uents in,  16. 

Tobacco,  338;  influence  of  fer- 
tilizer upon  quality,  339 ;  Con- 
necticut experiments,  339 ;  mu- 
riate of  potash,  95. 

Tobacco  stems,  103 ;   salts,  104. 

Tomatoes:  field  truck,  248;  mar- 
ket garden,  298. 

Ton  basis  of  purchase  of  fertilizer, 
157. 

Trade  values  of  fertilizers,  179; 
how  obtained,  181 ;  schedule  of, 
182. 

Tricalcic  phosphoric  acid,  82. 

Truck  crops,  see  Field  truck  crops, 
237. 

Tuber  crops,  282,  289. 

Turnips :  for  forage,  281 ;  for 
market  garden,  289. 

Uniformity  of  manufactured 
brands,  189. 

Unit  basis  of  purchase  of  fertilizers, 
157. 

Use  of  fertilizers :  conditions  which 
modify  usefulness  of  fertilizers, 
191 :  derivation  of  soil,  192 ; 
physical  imperfections  of  soil, 
194;  previous  treatment  of  soil, 
195 ;  character  of  crop,  197 ; 
kind  of  farming,  199. 

Variations  of  plants,  199 ;  cere- 
als, 200 ;  grasses  and  clovers,  200 ; 
root  crops,  202 ;  market  garden, 
202 ;  fruit  crops,  203. 

Systems  suggested  based  on : 


1.  influence  of  single  element, 
204;  2.  abundant  supply  of 
minerals,  205 ;  3.  needs  of  plant 
as  determined  by  chemical  analy- 
sis, 207 ;  4.  stimulation  of  the 
"money  crop"  in  the  rotation, 
209. 

Irrational  system,  210. 

Value  of  a  fertilizer,  178,  189. 

Variable  materials,  155. 

Vegetable  matter  in  fertilizers, 
effect  upon  physical  character  of 
the  soil,  21. 

Vegetable  nitrogenous  products, 
43 ;  pomaces,  44. 

Vegetables  (see  Market  garden 
crops),  202,  283;  fertilizer  con- 
stituents in,  16. 

Vetch :  spring,  272 ;  hairy  or 
winter,  272. 

Ville  George:  his  system  of  fer- 
tilizing, 204. 

Wages,  in  regard  to  fertilizers,  29, 
205. 

Wagner  system,  205. 

Waste:  calcium  carbide,  117;  wool 
and  hair,  43,  106;  powder,  116. 

Water,  its  influence  upon  soil  fer- 
tility, 3. 

Watermelons,  299. 

Wheat:  fertility  content  of,  14; 
fertilization,  224;  for  green 
forage,  263. 

Wiborgh  phosphate,  74. 

Winter  vetch,  272. 

Wolter  phosphate,  74. 

Wood  ashes,  111. 

Wool  waste,  43,  106. 


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ADDITIONS  TO  THE  RURAL  SCIENCE  SERIES 
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The  Pruning  Book 

By  L.  H.  BAILEY 

New  revised  and  rewritten  edition  with  new  illustrations,  cloih>  ismo 

Professor  Bailey  has  thoroughly  revised  his 
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Field  Crops  for  the  Cotton  Belt 

By  J.  O.  MORGAN 

Professor  of  Agronomy  in  the  Agricultural  and  Mechanical  College 
of  Texas 

Illustrated,  cloth,  izmo 

All  the  important  field  crops,  including  cot- 
ton, corn,  oats,  wheat,  rye,  barley,  rice,  sugar 
cane,  the  sweet  and  green  sorghums  and 
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and  marketing  thoroughly  discussed  from 
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The  Potato 


By  ARTHUR  W.  GILBERT 

Professor  of  Plant  Breeding  in  the  New  York  State  College  of  Agricul- 
ture.   Assisted  by  M.  W.  PEACOCK,  M.  F.  BARRUS,  and  others 


Illustrated,  cloth,  I2mo 

This  comprehensive  work  on  one  of  the  funda- 
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potatoes.  There  are  special  chapters  on  diseases 
of  potatoes  and  their  treatment  prepared  by  Dr. 
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culture and  chapters  on  the  machinery  and  prac- 
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who  is  instructor  in  Farm  Crops  at  the  New 
York  State  College  of  Agriculture  and  secretary 
of  the  New  York  Potato  Association. 


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The  Strawberry  in  North  America 
By  S.  W.  FLETCHER 

Illustrated,  cloth,  ismo 

This  work  is  not  only  a  practical  guide  to  strawberry  grow- 
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the  different  ways  in  which  it  is  practiced  in  different  parts 
of  the  country,  with  something  of  an  attempt  to  elucidate  the 
principles  that  underlie  these  practices. 

Subtropical  Vegetable-Gardening 
By  P.  H.  ROLFS 

Illustrated,  cloth,  I2tno 

This  work  is  a  distinct  contribution  to  the  literature  of 
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subtropical  experience,  but  his  book  will  prove  invaluable  to 
growers  in  a  wide  territory  of  the  United  States.  Definite 
information  is  given  regarding  production  of  various  crops 
and  all  new  or  unusual  vegetables  are  discussed. 


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